diff --git a/compiler/frontend.java/src/org/jetbrains/kotlin/synthetic/JavaSyntheticExtensionsScope.kt b/compiler/frontend.java/src/org/jetbrains/kotlin/synthetic/JavaSyntheticExtensionsScope.kt
index 1f756442c03..8d3c153763b 100644
--- a/compiler/frontend.java/src/org/jetbrains/kotlin/synthetic/JavaSyntheticExtensionsScope.kt
+++ b/compiler/frontend.java/src/org/jetbrains/kotlin/synthetic/JavaSyntheticExtensionsScope.kt
@@ -35,6 +35,7 @@ import org.jetbrains.kotlin.types.JetType
 import org.jetbrains.kotlin.types.TypeSubstitutor
 import org.jetbrains.kotlin.types.Variance
 import org.jetbrains.kotlin.types.typeUtil.isBoolean
+import org.jetbrains.kotlin.types.typeUtil.isSubtypeOf
 import org.jetbrains.kotlin.types.typeUtil.isUnit
 import org.jetbrains.kotlin.types.typeUtil.makeNotNullable
 import org.jetbrains.kotlin.util.capitalizeDecapitalize.capitalizeFirstWord
@@ -54,8 +55,7 @@ interface SyntheticJavaPropertyDescriptor : PropertyDescriptor {
             val identifier = name.getIdentifier()
             if (!identifier.startsWith("get") && !identifier.startsWith("is") && !identifier.startsWith("set")) return null // optimization
 
-            val owner = getterOrSetter.getContainingDeclaration()
-            if (owner !is JavaClassDescriptor) return null
+            val owner = getterOrSetter.getContainingDeclaration() as? ClassDescriptor ?: return null
 
             val originalGetterOrSetter = getterOrSetter.original
             return resolutionScope.getSyntheticExtensionProperties(listOf(owner.getDefaultType()))
@@ -94,50 +94,76 @@ class AdditionalScopesWithJavaSyntheticExtensions(storageManager: StorageManager
 }
 
 class JavaSyntheticExtensionsScope(storageManager: StorageManager) : JetScope by JetScope.Empty {
-    private val syntheticPropertyInClass = storageManager.createMemoizedFunctionWithNullableValues<Pair<JavaClassDescriptor, Name>, PropertyDescriptor> { pair ->
+    private val syntheticPropertyInClass = storageManager.createMemoizedFunctionWithNullableValues<Pair<ClassDescriptor, Name>, PropertyDescriptor> { pair ->
         syntheticPropertyInClassNotCached(pair.first, pair.second)
     }
 
-    private fun syntheticPropertyInClassNotCached(javaClass: JavaClassDescriptor, name: Name): PropertyDescriptor? {
+    private fun syntheticPropertyInClassNotCached(ownerClass: ClassDescriptor, name: Name): PropertyDescriptor? {
         if (name.isSpecial()) return null
         val identifier = name.identifier
         if (identifier.isEmpty()) return null
         val firstChar = identifier[0]
         if (!firstChar.isJavaIdentifierStart() || firstChar.isUpperCase()) return null
 
-        val memberScope = javaClass.getUnsubstitutedMemberScope()
+        val memberScope = ownerClass.unsubstitutedMemberScope
         val getMethod = possibleGetMethodNames(name)
                                 .asSequence()
                                 .flatMap { memberScope.getFunctions(it).asSequence() }
-                                .singleOrNull { it.kind != CallableMemberDescriptor.Kind.FAKE_OVERRIDE && isGoodGetMethod(it) } ?: return null
+                                .singleOrNull {
+                                    it.kind != CallableMemberDescriptor.Kind.FAKE_OVERRIDE && isGoodGetMethod(it) && it.hasJavaOriginInHierarchy()
+                                } ?: return null
 
         // don't accept "uRL" for "getURL" etc
         if (SyntheticJavaPropertyDescriptor.propertyNameByGetMethodName(getMethod.name) != name) return null
 
-        val propertyType = getMethod.getReturnType() ?: return null
-        val setMethod = memberScope.getFunctions(setMethodName(getMethod.getName()))
-                .singleOrNull { it.kind != CallableMemberDescriptor.Kind.FAKE_OVERRIDE && isGoodSetMethod(it, propertyType) }
+        val setMethod = memberScope.getFunctions(setMethodName(getMethod.name))
+                .singleOrNull { isGoodSetMethod(it, getMethod) }
 
-        return MyPropertyDescriptor(javaClass, getMethod.original, setMethod?.original, name, propertyType)
+        val propertyType = getMethod.returnType ?: return null
+        return MyPropertyDescriptor(ownerClass, getMethod.original, setMethod?.original, name, propertyType)
+    }
+
+    private fun FunctionDescriptor.hasJavaOriginInHierarchy(): Boolean {
+        return if (overriddenDescriptors.isEmpty())
+            containingDeclaration is JavaClassDescriptor
+        else
+            overriddenDescriptors.any { it.hasJavaOriginInHierarchy() }
     }
 
     private fun isGoodGetMethod(descriptor: FunctionDescriptor): Boolean {
-        val returnType = descriptor.getReturnType() ?: return false
+        val returnType = descriptor.returnType ?: return false
         if (returnType.isUnit()) return false
-        if (descriptor.getName().asString().startsWith("is") && !returnType.isBoolean()) return false
+        if (descriptor.name.asString().startsWith("is") && !returnType.isBoolean()) return false
 
-        return descriptor.getValueParameters().isEmpty()
-               && descriptor.getTypeParameters().isEmpty()
-               && descriptor.getVisibility() == Visibilities.PUBLIC //TODO: what about protected and package-local?
+        return descriptor.valueParameters.isEmpty()
+               && descriptor.typeParameters.isEmpty()
+               && descriptor.visibility == Visibilities.PUBLIC //TODO: what about protected and package-local?
     }
 
-    private fun isGoodSetMethod(descriptor: FunctionDescriptor, propertyType: JetType): Boolean {
-        val parameter = descriptor.getValueParameters().singleOrNull() ?: return false
-        return parameter.getType() == propertyType
-               && parameter.getVarargElementType() == null
-               && descriptor.getTypeParameters().isEmpty()
-               && descriptor.getReturnType()?.let { it.isUnit() } ?: false
-               && descriptor.getVisibility() == Visibilities.PUBLIC
+    private fun isGoodSetMethod(descriptor: FunctionDescriptor, getMethod: FunctionDescriptor): Boolean {
+        val propertyType = getMethod.returnType ?: return false
+        val parameter = descriptor.valueParameters.singleOrNull() ?: return false
+        if (parameter.type != propertyType) {
+            if (descriptor.kind != CallableMemberDescriptor.Kind.FAKE_OVERRIDE) return false // real setter must exactly match getter's type
+            if (!propertyType.isSubtypeOf(parameter.type)) return false
+            if (descriptor.findOverridden {
+                val baseProperty = SyntheticJavaPropertyDescriptor.findByGetterOrSetter(it, this)
+                baseProperty?.getMethod?.name == getMethod.name
+            } == null) return false
+        }
+
+        return parameter.varargElementType == null
+               && descriptor.typeParameters.isEmpty()
+               && descriptor.returnType?.let { it.isUnit() } ?: false
+               && descriptor.visibility == Visibilities.PUBLIC
+    }
+
+    private fun FunctionDescriptor.findOverridden(condition: (FunctionDescriptor) -> Boolean): FunctionDescriptor? {
+        for (descriptor in overriddenDescriptors) {
+            if (condition(descriptor)) return descriptor
+            descriptor.findOverridden(condition)?.let { return it }
+        }
+        return null
     }
 
     override fun getSyntheticExtensionProperties(receiverTypes: Collection<JetType>, name: Name): Collection<PropertyDescriptor> {
@@ -161,7 +187,7 @@ class JavaSyntheticExtensionsScope(storageManager: StorageManager) : JetScope by
 
         val typeConstructor = type.getConstructor()
         val classifier = typeConstructor.getDeclarationDescriptor()
-        if (classifier is JavaClassDescriptor) {
+        if (classifier is ClassDescriptor) {
             result = result.add(syntheticPropertyInClass(Pair(classifier, name)))
         }
 
@@ -184,7 +210,7 @@ class JavaSyntheticExtensionsScope(storageManager: StorageManager) : JetScope by
 
         val typeConstructor = type.getConstructor()
         val classifier = typeConstructor.getDeclarationDescriptor()
-        if (classifier is JavaClassDescriptor) {
+        if (classifier is ClassDescriptor) {
             for (descriptor in classifier.getUnsubstitutedMemberScope().getDescriptors(DescriptorKindFilter.FUNCTIONS)) {
                 if (descriptor is FunctionDescriptor) {
                     val propertyName = SyntheticJavaPropertyDescriptor.propertyNameByGetMethodName(descriptor.getName()) ?: continue
@@ -233,13 +259,13 @@ class JavaSyntheticExtensionsScope(storageManager: StorageManager) : JetScope by
     }
 
     private class MyPropertyDescriptor(
-            javaClass: JavaClassDescriptor,
+            ownerClass: ClassDescriptor,
             override val getMethod: FunctionDescriptor,
             override val setMethod: FunctionDescriptor?,
             name: Name,
             type: JetType
     ) : SyntheticJavaPropertyDescriptor, PropertyDescriptorImpl(
-            DescriptorUtils.getContainingModule(javaClass)/* TODO:is it ok? */,
+            DescriptorUtils.getContainingModule(ownerClass)/* TODO:is it ok? */,
             null,
             Annotations.EMPTY,
             Modality.FINAL,
@@ -250,12 +276,12 @@ class JavaSyntheticExtensionsScope(storageManager: StorageManager) : JetScope by
             SourceElement.NO_SOURCE/*TODO?*/
     ) {
         init {
-            val classTypeParams = javaClass.typeConstructor.parameters
+            val classTypeParams = ownerClass.typeConstructor.parameters
             val typeParameters = ArrayList<TypeParameterDescriptor>(classTypeParams.size())
             val typeSubstitutor = DescriptorSubstitutor.substituteTypeParameters(classTypeParams, TypeSubstitutor.EMPTY, this, typeParameters)
 
             val propertyType = typeSubstitutor.safeSubstitute(type, Variance.INVARIANT)
-            val receiverType = typeSubstitutor.safeSubstitute(javaClass.defaultType, Variance.INVARIANT)
+            val receiverType = typeSubstitutor.safeSubstitute(ownerClass.defaultType, Variance.INVARIANT)
             setType(propertyType, typeParameters, null, receiverType)
 
             val getter = PropertyGetterDescriptorImpl(this,
diff --git a/compiler/testData/codegen/boxAgainstJava/syntheticExtensions/overrideOnlyGetter.java b/compiler/testData/codegen/boxAgainstJava/syntheticExtensions/overrideOnlyGetter.java
new file mode 100644
index 00000000000..4a7ab421bc5
--- /dev/null
+++ b/compiler/testData/codegen/boxAgainstJava/syntheticExtensions/overrideOnlyGetter.java
@@ -0,0 +1,10 @@
+class JavaClass1 {
+    protected Object value = null;
+
+    public Object getSomething() { return null; }
+    public void setSomething(Object value) {  this.value = value; }
+}
+
+class JavaClass2 extends JavaClass1 {
+    public String getSomething() { return (String)value; }
+}
diff --git a/compiler/testData/codegen/boxAgainstJava/syntheticExtensions/overrideOnlyGetter.kt b/compiler/testData/codegen/boxAgainstJava/syntheticExtensions/overrideOnlyGetter.kt
new file mode 100644
index 00000000000..cd8d6552080
--- /dev/null
+++ b/compiler/testData/codegen/boxAgainstJava/syntheticExtensions/overrideOnlyGetter.kt
@@ -0,0 +1,5 @@
+fun box(): String {
+    val javaClass = JavaClass2()
+    javaClass.something = "OK"
+    return javaClass.something
+}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/JavaOverridesKotlin.kt b/compiler/testData/diagnostics/tests/syntheticExtensions/JavaOverridesKotlin.kt
new file mode 100644
index 00000000000..ca18c9b15bc
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/JavaOverridesKotlin.kt
@@ -0,0 +1,29 @@
+// FILE: KotlinFile.kt
+open class KotlinClass {
+    public open fun getSomething1(): Int = 1
+
+    public open fun setSomething2(value: Int) {}
+}
+
+fun foo(javaClass: JavaClass) {
+    useInt(javaClass.getSomething1())
+    useInt(javaClass.<!UNRESOLVED_REFERENCE!>something1<!>)
+
+    javaClass.setSomething2(javaClass.getSomething2() + 1)
+    javaClass.something2 = javaClass.something2 + 1
+}
+
+fun useInt(<!UNUSED_PARAMETER!>i<!>: Int) {}
+
+// FILE: JavaClass.java
+public class JavaClass extends KotlinClass implements JavaInterface {
+    public int getSomething1() { return 1; }
+
+    public int getSomething2() { return 1; }
+    public void setSomething2(int value) {}
+}
+
+// FILE: JavaInterface.java
+public class JavaInterface {
+    int getSomething2();
+}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/JavaOverridesKotlin.txt b/compiler/testData/diagnostics/tests/syntheticExtensions/JavaOverridesKotlin.txt
new file mode 100644
index 00000000000..85484900fc5
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/JavaOverridesKotlin.txt
@@ -0,0 +1,31 @@
+package
+
+internal fun foo(/*0*/ javaClass: JavaClass): kotlin.Unit
+internal fun useInt(/*0*/ i: kotlin.Int): kotlin.Unit
+
+public open class JavaClass : KotlinClass, JavaInterface {
+    public constructor JavaClass()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ fun getSomething1(): kotlin.Int
+    public open override /*1*/ fun getSomething2(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ fun setSomething2(/*0*/ value: kotlin.Int): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public open class JavaInterface {
+    public constructor JavaInterface()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public/*package*/ open fun getSomething2(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal open class KotlinClass {
+    public constructor KotlinClass()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun getSomething1(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open fun setSomething2(/*0*/ value: kotlin.Int): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava.kt b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava.kt
new file mode 100644
index 00000000000..bbebad6f852
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava.kt
@@ -0,0 +1,52 @@
+// FILE: KotlinFile.kt
+abstract class KotlinClass : JavaClass(), KotlinInterface, JavaInterface {
+    override fun getSomething1(): Int = 1
+    override fun getSomething3(): String = ""
+    override fun setSomething4(value: String) {}
+    override fun getSomething5(): String = ""
+}
+
+interface KotlinInterface {
+    public fun getSomething1(): Int
+    public fun getSomething4(): String
+}
+
+fun foo(k: KotlinClass) {
+    useInt(k.getSomething1())
+    useInt(k.something1)
+
+    useInt(k.getSomething2())
+    useInt(k.something2)
+
+    useString(k.getSomething3())
+    useString(k.something3)
+
+    k.setSomething4("")
+    k.something4 += ""
+    k.setSomething4(<!NULL_FOR_NONNULL_TYPE!>null<!>)
+    k.something4 = null
+
+    useString(k.getSomething5())
+    useString(k.something5)
+    k.setSomething5(1)
+    k.something5 = <!CONSTANT_EXPECTED_TYPE_MISMATCH!>1<!>
+}
+
+fun useInt(<!UNUSED_PARAMETER!>i<!>: Int) {}
+fun useString(<!UNUSED_PARAMETER!>i<!>: String) {}
+
+// FILE: JavaClass.java
+public class JavaClass {
+    public int getSomething1() { return 1; }
+    public int getSomething2() { return 1; }
+    public Object getSomething3() { return null; }
+}
+
+// FILE: JavaInterface.java
+public interface JavaInterface {
+    String getSomething4();
+    void setSomething4(String value);
+
+    Object getSomething5();
+    void setSomething5(Object value);
+}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava.txt b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava.txt
new file mode 100644
index 00000000000..a48f3c46a49
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava.txt
@@ -0,0 +1,47 @@
+package
+
+internal fun foo(/*0*/ k: KotlinClass): kotlin.Unit
+internal fun useInt(/*0*/ i: kotlin.Int): kotlin.Unit
+internal fun useString(/*0*/ i: kotlin.String): kotlin.Unit
+
+public open class JavaClass {
+    public constructor JavaClass()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun getSomething1(): kotlin.Int
+    public open fun getSomething2(): kotlin.Int
+    public open fun getSomething3(): kotlin.Any!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface JavaInterface {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun getSomething4(): kotlin.String!
+    public abstract fun getSomething5(): kotlin.Any!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun setSomething4(/*0*/ value: kotlin.String!): kotlin.Unit
+    public abstract fun setSomething5(/*0*/ value: kotlin.Any!): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal abstract class KotlinClass : JavaClass, KotlinInterface, JavaInterface {
+    public constructor KotlinClass()
+    public open override /*3*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ fun getSomething1(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun getSomething2(): kotlin.Int
+    public open override /*1*/ fun getSomething3(): kotlin.String
+    public abstract override /*2*/ /*fake_override*/ fun getSomething4(): kotlin.String!
+    public open override /*1*/ fun getSomething5(): kotlin.String
+    public open override /*3*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ fun setSomething4(/*0*/ value: kotlin.String): kotlin.Unit
+    public abstract override /*1*/ /*fake_override*/ fun setSomething5(/*0*/ value: kotlin.Any!): kotlin.Unit
+    public open override /*3*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal interface KotlinInterface {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun getSomething1(): kotlin.Int
+    public abstract fun getSomething4(): kotlin.String
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava2.kt b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava2.kt
new file mode 100644
index 00000000000..fadda63cd94
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava2.kt
@@ -0,0 +1,25 @@
+// FILE: KotlinFile.kt
+abstract class KotlinClass : JavaInterface1, JavaInterface2 {
+    override fun getSomething(): String = ""
+}
+
+fun foo(k: KotlinClass) {
+    useString(k.getSomething())
+    useString(k.something)
+    if (<!SENSELESS_COMPARISON!>k.something == null<!>) return
+
+    k.setSomething(1)
+    <!VAL_REASSIGNMENT!>k.something<!> = <!CONSTANT_EXPECTED_TYPE_MISMATCH!>1<!>
+}
+
+fun useString(<!UNUSED_PARAMETER!>i<!>: String) {}
+
+// FILE: JavaInterface1.java
+public interface JavaInterface1 {
+    String getSomething();
+}
+
+// FILE: JavaInterface2.java
+public interface JavaInterface2 {
+    void setSomething(int value);
+}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava2.txt b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava2.txt
new file mode 100644
index 00000000000..50f76abf47e
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava2.txt
@@ -0,0 +1,29 @@
+package
+
+public /*synthesized*/ fun JavaInterface1(/*0*/ function: () -> kotlin.String!): JavaInterface1
+public /*synthesized*/ fun JavaInterface2(/*0*/ function: (kotlin.Int) -> kotlin.Unit): JavaInterface2
+internal fun foo(/*0*/ k: KotlinClass): kotlin.Unit
+internal fun useString(/*0*/ i: kotlin.String): kotlin.Unit
+
+public interface JavaInterface1 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun getSomething(): kotlin.String!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface JavaInterface2 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun setSomething(/*0*/ value: kotlin.Int): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal abstract class KotlinClass : JavaInterface1, JavaInterface2 {
+    public constructor KotlinClass()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ fun getSomething(): kotlin.String
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun setSomething(/*0*/ value: kotlin.Int): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava3.kt b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava3.kt
new file mode 100644
index 00000000000..7af74313db4
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava3.kt
@@ -0,0 +1,25 @@
+// FILE: KotlinFile.kt
+abstract class KotlinClass : JavaInterface1, JavaInterface2 {
+    override fun getSomething(): String = ""
+}
+
+fun foo(k: KotlinClass) {
+    useString(k.getSomething())
+    useString(k.something)
+    if (<!SENSELESS_COMPARISON!>k.something == null<!>) return
+
+    k.setSomething("")
+    <!VAL_REASSIGNMENT!>k.something<!> = ""
+}
+
+fun useString(<!UNUSED_PARAMETER!>i<!>: String) {}
+
+// FILE: JavaInterface1.java
+public interface JavaInterface1 {
+    String getSomething();
+}
+
+// FILE: JavaInterface2.java
+public interface JavaInterface2 {
+    void setSomething(String value);
+}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava3.txt b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava3.txt
new file mode 100644
index 00000000000..dab991a8dcf
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava3.txt
@@ -0,0 +1,29 @@
+package
+
+public /*synthesized*/ fun JavaInterface1(/*0*/ function: () -> kotlin.String!): JavaInterface1
+public /*synthesized*/ fun JavaInterface2(/*0*/ function: (kotlin.String!) -> kotlin.Unit): JavaInterface2
+internal fun foo(/*0*/ k: KotlinClass): kotlin.Unit
+internal fun useString(/*0*/ i: kotlin.String): kotlin.Unit
+
+public interface JavaInterface1 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun getSomething(): kotlin.String!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface JavaInterface2 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun setSomething(/*0*/ value: kotlin.String!): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal abstract class KotlinClass : JavaInterface1, JavaInterface2 {
+    public constructor KotlinClass()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ fun getSomething(): kotlin.String
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun setSomething(/*0*/ value: kotlin.String!): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava4.kt b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava4.kt
new file mode 100644
index 00000000000..a53a67f5084
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava4.kt
@@ -0,0 +1,28 @@
+// FILE: KotlinFile.kt
+abstract class KotlinClass : JavaInterface3 {
+    override fun getSomething(): String = ""
+}
+
+fun foo(k: KotlinClass) {
+    useString(k.getSomething())
+    useString(k.something)
+    if (<!SENSELESS_COMPARISON!>k.something == null<!>) return
+
+    k.setSomething("")
+    <!VAL_REASSIGNMENT!>k.something<!> = ""
+}
+
+fun useString(<!UNUSED_PARAMETER!>i<!>: String) {}
+
+// FILE: JavaInterface1.java
+public interface JavaInterface1 {
+    String getSomething();
+}
+
+// FILE: JavaInterface2.java
+public interface JavaInterface2 {
+    void setSomething(String value);
+}
+
+// FILE: JavaInterface3.java
+public interface JavaInterface3 extends JavaInterface1, JavaInterface2 {}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava4.txt b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava4.txt
new file mode 100644
index 00000000000..4d1dff211de
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava4.txt
@@ -0,0 +1,37 @@
+package
+
+public /*synthesized*/ fun JavaInterface1(/*0*/ function: () -> kotlin.String!): JavaInterface1
+public /*synthesized*/ fun JavaInterface2(/*0*/ function: (kotlin.String!) -> kotlin.Unit): JavaInterface2
+internal fun foo(/*0*/ k: KotlinClass): kotlin.Unit
+internal fun useString(/*0*/ i: kotlin.String): kotlin.Unit
+
+public interface JavaInterface1 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun getSomething(): kotlin.String!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface JavaInterface2 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun setSomething(/*0*/ value: kotlin.String!): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface JavaInterface3 : JavaInterface1, JavaInterface2 {
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*1*/ /*fake_override*/ fun getSomething(): kotlin.String!
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun setSomething(/*0*/ value: kotlin.String!): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal abstract class KotlinClass : JavaInterface3 {
+    public constructor KotlinClass()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ fun getSomething(): kotlin.String
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun setSomething(/*0*/ value: kotlin.String!): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava5.kt b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava5.kt
new file mode 100644
index 00000000000..69e516b4abc
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava5.kt
@@ -0,0 +1,29 @@
+// FILE: KotlinFile.kt
+abstract class KotlinClass : JavaInterface3 {
+    override fun getSomething(): String = ""
+}
+
+fun foo(k: KotlinClass) {
+    useString(k.getSomething())
+    useString(k.something)
+    if (<!SENSELESS_COMPARISON!>k.something == null<!>) return
+
+    k.setSomething("")
+    k.something = ""
+}
+
+fun useString(<!UNUSED_PARAMETER!>i<!>: String) {}
+
+// FILE: JavaInterface1.java
+public interface JavaInterface1 {
+    String getSomething();
+}
+
+// FILE: JavaInterface2.java
+public interface JavaInterface2 {
+    String getSomething();
+    void setSomething(String value);
+}
+
+// FILE: JavaInterface3.java
+public interface JavaInterface3 extends JavaInterface1, JavaInterface2 {}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava5.txt b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava5.txt
new file mode 100644
index 00000000000..7f113511b9c
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava5.txt
@@ -0,0 +1,37 @@
+package
+
+public /*synthesized*/ fun JavaInterface1(/*0*/ function: () -> kotlin.String!): JavaInterface1
+internal fun foo(/*0*/ k: KotlinClass): kotlin.Unit
+internal fun useString(/*0*/ i: kotlin.String): kotlin.Unit
+
+public interface JavaInterface1 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun getSomething(): kotlin.String!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface JavaInterface2 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun getSomething(): kotlin.String!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun setSomething(/*0*/ value: kotlin.String!): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface JavaInterface3 : JavaInterface1, JavaInterface2 {
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*2*/ /*fake_override*/ fun getSomething(): kotlin.String!
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun setSomething(/*0*/ value: kotlin.String!): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal abstract class KotlinClass : JavaInterface3 {
+    public constructor KotlinClass()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ fun getSomething(): kotlin.String
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun setSomething(/*0*/ value: kotlin.String!): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/OverrideGetterOnly.kt b/compiler/testData/diagnostics/tests/syntheticExtensions/OverrideGetterOnly.kt
new file mode 100644
index 00000000000..c8e14d5333b
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/OverrideGetterOnly.kt
@@ -0,0 +1,22 @@
+// FILE: KotlinFile.kt
+
+fun foo(o: JavaClass2) {
+    useString(o.something)
+    o.something = ""
+    o.setSomething(1)
+    o.something = <!CONSTANT_EXPECTED_TYPE_MISMATCH!>1<!> // we generate extension property for JavaClass2 with more specific type
+    o.something += "1"
+}
+
+fun useString(<!UNUSED_PARAMETER!>i<!>: String) {}
+
+// FILE: JavaClass1.java
+public class JavaClass1 {
+    public Object getSomething() { return null; }
+    public void setSomething(Object value) { }
+}
+
+// FILE: JavaClass2.java
+public class JavaClass2 extends JavaClass1 {
+    public String getSomething() { return ""; }
+}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/syntheticExtensions/OverrideGetterOnly.txt b/compiler/testData/diagnostics/tests/syntheticExtensions/OverrideGetterOnly.txt
new file mode 100644
index 00000000000..d49adc526da
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/syntheticExtensions/OverrideGetterOnly.txt
@@ -0,0 +1,22 @@
+package
+
+internal fun foo(/*0*/ o: JavaClass2): kotlin.Unit
+internal fun useString(/*0*/ i: kotlin.String): kotlin.Unit
+
+public open class JavaClass1 {
+    public constructor JavaClass1()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun getSomething(): kotlin.Any!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open fun setSomething(/*0*/ value: kotlin.Any!): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public open class JavaClass2 : JavaClass1 {
+    public constructor JavaClass2()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ fun getSomething(): kotlin.String!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun setSomething(/*0*/ value: kotlin.Any!): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java
index 4de00ef2cf9..9609029d56a 100644
--- a/compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java
@@ -14082,12 +14082,54 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("JavaOverridesKotlin.kt")
+            public void testJavaOverridesKotlin() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/syntheticExtensions/JavaOverridesKotlin.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("KotlinOverridesJava.kt")
+            public void testKotlinOverridesJava() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("KotlinOverridesJava2.kt")
+            public void testKotlinOverridesJava2() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava2.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("KotlinOverridesJava3.kt")
+            public void testKotlinOverridesJava3() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava3.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("KotlinOverridesJava4.kt")
+            public void testKotlinOverridesJava4() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava4.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("KotlinOverridesJava5.kt")
+            public void testKotlinOverridesJava5() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/syntheticExtensions/KotlinOverridesJava5.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("OnlyPublic.kt")
             public void testOnlyPublic() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/syntheticExtensions/OnlyPublic.kt");
                 doTest(fileName);
             }
 
+            @TestMetadata("OverrideGetterOnly.kt")
+            public void testOverrideGetterOnly() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/syntheticExtensions/OverrideGetterOnly.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("SetterOnly.kt")
             public void testSetterOnly() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/syntheticExtensions/SetterOnly.kt");
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxAgainstJavaCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxAgainstJavaCodegenTestGenerated.java
index 040a22f3ef9..86f18641a95 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxAgainstJavaCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxAgainstJavaCodegenTestGenerated.java
@@ -847,6 +847,12 @@ public class BlackBoxAgainstJavaCodegenTestGenerated extends AbstractBlackBoxCod
             doTestAgainstJava(fileName);
         }
 
+        @TestMetadata("overrideOnlyGetter.kt")
+        public void testOverrideOnlyGetter() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxAgainstJava/syntheticExtensions/overrideOnlyGetter.kt");
+            doTestAgainstJava(fileName);
+        }
+
         @TestMetadata("plusPlus.kt")
         public void testPlusPlus() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxAgainstJava/syntheticExtensions/plusPlus.kt");