diff --git a/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/TopDownAnalyzerFacadeForJVM.kt b/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/TopDownAnalyzerFacadeForJVM.kt
index 684b5d7907c..a8421b4a9e5 100644
--- a/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/TopDownAnalyzerFacadeForJVM.kt
+++ b/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/TopDownAnalyzerFacadeForJVM.kt
@@ -227,10 +227,10 @@ object TopDownAnalyzerFacadeForJVM {
         }
 
         // TODO: remove dependencyModule from friends
-        module.setDependencies(ModuleDependenciesImpl(
+        module.setDependencies(
                 listOfNotNull(module, dependencyModule, optionalBuiltInsModule),
                 if (dependencyModule != null) setOf(dependencyModule) else emptySet()
-        ))
+        )
         module.initialize(CompositePackageFragmentProvider(
                 listOf(container.get<KotlinCodeAnalyzer>().packageFragmentProvider) +
                 additionalProviders
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/analyzer/AnalyzerFacade.kt b/compiler/frontend/src/org/jetbrains/kotlin/analyzer/AnalyzerFacade.kt
index 82178086c8b..3ef7d72b057 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/analyzer/AnalyzerFacade.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/analyzer/AnalyzerFacade.kt
@@ -44,6 +44,7 @@ import org.jetbrains.kotlin.resolve.MultiTargetPlatform
 import org.jetbrains.kotlin.resolve.TargetEnvironment
 import org.jetbrains.kotlin.resolve.TargetPlatform
 import org.jetbrains.kotlin.storage.StorageManager
+import org.jetbrains.kotlin.storage.getValue
 import java.util.*
 import kotlin.coroutines.experimental.buildSequence
 
@@ -307,6 +308,10 @@ class LazyModuleDependencies<M : ModuleInfo>(
 
     override val allDependencies: List<ModuleDescriptorImpl> get() = dependencies()
 
+    override val expectedByDependency by storageManager.createNullableLazyValue {
+        module.expectedBy?.let { resolverForProject.descriptorForModule(it as M) }
+    }
+
     override val modulesWhoseInternalsAreVisible: Set<ModuleDescriptorImpl>
         get() =
             module.modulesWhoseInternalsAreVisible().mapTo(LinkedHashSet()) {
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExpectedActualDeclarationChecker.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExpectedActualDeclarationChecker.kt
index 72a6fa60419..9e8ab2ca4a0 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExpectedActualDeclarationChecker.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExpectedActualDeclarationChecker.kt
@@ -110,10 +110,12 @@ object ExpectedActualDeclarationChecker : DeclarationChecker {
     private fun checkActualDeclarationHasExpected(
         reportOn: KtNamedDeclaration, descriptor: MemberDescriptor, trace: BindingTrace, checkActual: Boolean
     ) {
-        // Using the platform module instead of the common module is sort of fine here because the former always depends on the latter.
-        // However, it would be clearer to find the common module this platform module implements and look for expected there instead.
-        // TODO: use common module here
-        val compatibility = ExpectedActualResolver.findExpectedForActual(descriptor, descriptor.module) ?: return
+        // TODO: ideally, we should always use common module here
+        // However, in compiler context platform & common modules are joined into one module,
+        // so there is yet no "common module" in this situation.
+        // So yet we are using own module in compiler context and common module in IDE context.
+        val commonOrOwnModule = descriptor.module.expectedByModule ?: descriptor.module
+        val compatibility = ExpectedActualResolver.findExpectedForActual(descriptor, commonOrOwnModule) ?: return
 
         val hasActualModifier = descriptor.isActual && reportOn.hasActualModifier()
         if (!hasActualModifier) {
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/ModuleDescriptor.kt b/core/descriptors/src/org/jetbrains/kotlin/descriptors/ModuleDescriptor.kt
index d5a2164a41a..7035dfabb8f 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/ModuleDescriptor.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/ModuleDescriptor.kt
@@ -40,6 +40,8 @@ interface ModuleDescriptor : DeclarationDescriptor {
      */
     val allDependencyModules: List<ModuleDescriptor>
 
+    val expectedByModule: ModuleDescriptor?
+
     fun <T> getCapability(capability: Capability<T>): T?
 
     class Capability<T>(val name: String) {
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt
index e7c6862df9f..8c7dce58219 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt
@@ -66,6 +66,9 @@ class ModuleDescriptorImpl @JvmOverloads constructor(
     override val allDependencyModules: List<ModuleDescriptor>
         get() = this.dependencies.sure { "Dependencies of module $id were not set" }.allDependencies.filter { it != this }
 
+    override val expectedByModule: ModuleDescriptor?
+        get() = this.dependencies.sure { "Dependencies of module $id were not set" }.expectedByDependency
+
     override fun getPackage(fqName: FqName): PackageViewDescriptor {
         assertValid()
         return packages(fqName)
@@ -104,11 +107,11 @@ class ModuleDescriptorImpl @JvmOverloads constructor(
     }
 
     fun setDependencies(descriptors: List<ModuleDescriptorImpl>) {
-        setDependencies(ModuleDependenciesImpl(descriptors, emptySet()))
+        setDependencies(descriptors, emptySet())
     }
 
     fun setDependencies(descriptors: List<ModuleDescriptorImpl>, friends: Set<ModuleDescriptorImpl>) {
-        setDependencies(ModuleDependenciesImpl(descriptors, friends))
+        setDependencies(ModuleDependenciesImpl(descriptors, friends, null))
     }
 
     override fun shouldSeeInternalsOf(targetModule: ModuleDescriptor): Boolean {
@@ -147,9 +150,11 @@ class ModuleDescriptorImpl @JvmOverloads constructor(
 interface ModuleDependencies {
     val allDependencies: List<ModuleDescriptorImpl>
     val modulesWhoseInternalsAreVisible: Set<ModuleDescriptorImpl>
+    val expectedByDependency: ModuleDescriptorImpl?
 }
 
 class ModuleDependenciesImpl(
-        override val allDependencies: List<ModuleDescriptorImpl>,
-        override val modulesWhoseInternalsAreVisible: Set<ModuleDescriptorImpl>
+    override val allDependencies: List<ModuleDescriptorImpl>,
+    override val modulesWhoseInternalsAreVisible: Set<ModuleDescriptorImpl>,
+    override val expectedByDependency: ModuleDescriptorImpl?
 ) : ModuleDependencies
diff --git a/core/descriptors/src/org/jetbrains/kotlin/types/ErrorUtils.java b/core/descriptors/src/org/jetbrains/kotlin/types/ErrorUtils.java
index 9216637bc9a..ae2bd983b6a 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/types/ErrorUtils.java
+++ b/core/descriptors/src/org/jetbrains/kotlin/types/ErrorUtils.java
@@ -85,6 +85,12 @@ public class ErrorUtils {
                 return emptyList();
             }
 
+            @Nullable
+            @Override
+            public ModuleDescriptor getExpectedByModule() {
+                return null;
+            }
+
             @Override
             public <R, D> R accept(@NotNull DeclarationDescriptorVisitor<R, D> visitor, D data) {
                 return null;
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/basic/jvm/jvm.kt b/idea/testData/multiModuleHighlighting/multiplatform/basic/jvm/jvm.kt
index 2634e8e96bf..d513b858280 100644
--- a/idea/testData/multiModuleHighlighting/multiplatform/basic/jvm/jvm.kt
+++ b/idea/testData/multiModuleHighlighting/multiplatform/basic/jvm/jvm.kt
@@ -10,6 +10,6 @@ expect class Their {
 
 }
 
-actual class Their {
+actual class <error descr="[ACTUAL_WITHOUT_EXPECT] Actual class 'Their' has no corresponding expected declaration">Their</error> {
 
 }
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/depends/common/common.kt b/idea/testData/multiModuleHighlighting/multiplatform/depends/common/common.kt
new file mode 100644
index 00000000000..2b091d063d1
--- /dev/null
+++ b/idea/testData/multiModuleHighlighting/multiplatform/depends/common/common.kt
@@ -0,0 +1 @@
+expect class My
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/depends/jvm/jvm.kt b/idea/testData/multiModuleHighlighting/multiplatform/depends/jvm/jvm.kt
new file mode 100644
index 00000000000..43ec49aaf7a
--- /dev/null
+++ b/idea/testData/multiModuleHighlighting/multiplatform/depends/jvm/jvm.kt
@@ -0,0 +1 @@
+class <error descr="[ACTUAL_MISSING] Declaration must be marked with 'actual'">My</error>
\ No newline at end of file
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/triangle/common_base/My.kt b/idea/testData/multiModuleHighlighting/multiplatform/triangle/common_base/My.kt
new file mode 100644
index 00000000000..023d50bcba5
--- /dev/null
+++ b/idea/testData/multiModuleHighlighting/multiplatform/triangle/common_base/My.kt
@@ -0,0 +1 @@
+expect class My
\ No newline at end of file
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/triangle/common_derived/foo.kt b/idea/testData/multiModuleHighlighting/multiplatform/triangle/common_derived/foo.kt
new file mode 100644
index 00000000000..32ace5627a5
--- /dev/null
+++ b/idea/testData/multiModuleHighlighting/multiplatform/triangle/common_derived/foo.kt
@@ -0,0 +1 @@
+expect fun foo(my: Any)
\ No newline at end of file
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/triangle/jvm_derived/impl.kt b/idea/testData/multiModuleHighlighting/multiplatform/triangle/jvm_derived/impl.kt
new file mode 100644
index 00000000000..24e8106e93f
--- /dev/null
+++ b/idea/testData/multiModuleHighlighting/multiplatform/triangle/jvm_derived/impl.kt
@@ -0,0 +1,3 @@
+class My
+
+actual fun foo(my: Any) {}
\ No newline at end of file
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/triangleWithDependency/common_base/My.kt b/idea/testData/multiModuleHighlighting/multiplatform/triangleWithDependency/common_base/My.kt
new file mode 100644
index 00000000000..023d50bcba5
--- /dev/null
+++ b/idea/testData/multiModuleHighlighting/multiplatform/triangleWithDependency/common_base/My.kt
@@ -0,0 +1 @@
+expect class My
\ No newline at end of file
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/triangleWithDependency/common_derived/foo.kt b/idea/testData/multiModuleHighlighting/multiplatform/triangleWithDependency/common_derived/foo.kt
new file mode 100644
index 00000000000..a8508a1a779
--- /dev/null
+++ b/idea/testData/multiModuleHighlighting/multiplatform/triangleWithDependency/common_derived/foo.kt
@@ -0,0 +1 @@
+expect fun foo(my: My)
\ No newline at end of file
diff --git a/idea/testData/multiModuleHighlighting/multiplatform/triangleWithDependency/jvm_derived/impl.kt b/idea/testData/multiModuleHighlighting/multiplatform/triangleWithDependency/jvm_derived/impl.kt
new file mode 100644
index 00000000000..c79e944e0ce
--- /dev/null
+++ b/idea/testData/multiModuleHighlighting/multiplatform/triangleWithDependency/jvm_derived/impl.kt
@@ -0,0 +1,3 @@
+class <error descr="[ACTUAL_MISSING] Declaration must be marked with 'actual'">My</error>
+
+actual fun foo(my: My) {}
\ No newline at end of file
diff --git a/idea/tests/org/jetbrains/kotlin/idea/caches/resolve/MultiPlatformHighlightingTest.kt b/idea/tests/org/jetbrains/kotlin/idea/caches/resolve/MultiPlatformHighlightingTest.kt
index f742dd3d10c..d71c7a943c5 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/caches/resolve/MultiPlatformHighlightingTest.kt
+++ b/idea/tests/org/jetbrains/kotlin/idea/caches/resolve/MultiPlatformHighlightingTest.kt
@@ -33,6 +33,20 @@ class MultiPlatformHighlightingTest : AbstractMultiModuleHighlightingTest() {
         doMultiPlatformTest(TargetPlatformKind.Jvm[JvmTarget.JVM_1_6])
     }
 
+    fun testDepends() {
+        val commonModule = module("common", TestJdkKind.MOCK_JDK)
+        commonModule.createFacet(TargetPlatformKind.Common)
+        commonModule.enableMultiPlatform()
+
+        val jvmPlatform = TargetPlatformKind.Jvm[JvmTarget.JVM_1_6]
+        val jvmModule = module("jvm", TestJdkKind.MOCK_JDK)
+        jvmModule.createFacet(jvmPlatform)
+        jvmModule.enableMultiPlatform()
+        jvmModule.addDependency(commonModule)
+
+        checkHighlightingInAllFiles()
+    }
+
     fun testHeaderClass() {
         doMultiPlatformTest(TargetPlatformKind.Jvm[JvmTarget.JVM_1_6])
     }
@@ -106,4 +120,40 @@ class MultiPlatformHighlightingTest : AbstractMultiModuleHighlightingTest() {
         checkHighlightingInAllFiles()
     }
 
+    fun testTriangle() {
+        val commonModule = module("common_base", TestJdkKind.MOCK_JDK)
+        commonModule.createFacet(TargetPlatformKind.Common, false)
+
+        val derivedModule = module("common_derived", TestJdkKind.MOCK_JDK)
+        derivedModule.createFacet(TargetPlatformKind.Common)
+        derivedModule.enableMultiPlatform()
+
+        val jvmPlatform = TargetPlatformKind.Jvm[JvmTarget.JVM_1_6]
+        val jvmModule = module("jvm_derived", TestJdkKind.MOCK_JDK)
+        jvmModule.createFacet(jvmPlatform, implementedModuleName = "common_derived")
+        jvmModule.enableMultiPlatform()
+        jvmModule.addDependency(commonModule)
+        jvmModule.addDependency(derivedModule)
+
+        checkHighlightingInAllFiles()
+    }
+
+    fun testTriangleWithDependency() {
+        val commonModule = module("common_base", TestJdkKind.MOCK_JDK)
+        commonModule.createFacet(TargetPlatformKind.Common, false)
+
+        val derivedModule = module("common_derived", TestJdkKind.MOCK_JDK)
+        derivedModule.createFacet(TargetPlatformKind.Common)
+        derivedModule.enableMultiPlatform()
+        derivedModule.addDependency(commonModule)
+
+        val jvmPlatform = TargetPlatformKind.Jvm[JvmTarget.JVM_1_6]
+        val jvmModule = module("jvm_derived", TestJdkKind.MOCK_JDK)
+        jvmModule.createFacet(jvmPlatform, implementedModuleName = "common_derived")
+        jvmModule.enableMultiPlatform()
+        jvmModule.addDependency(commonModule)
+        jvmModule.addDependency(derivedModule)
+
+        checkHighlightingInAllFiles()
+    }
 }
\ No newline at end of file