diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/PropertyCodegen.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/PropertyCodegen.java
index 0cf157089a1..be2f35dfee0 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/PropertyCodegen.java
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/PropertyCodegen.java
@@ -210,6 +210,12 @@ public class PropertyCodegen {
             return !isDefaultAccessor;
         }
 
+        // Non-private properties with private setter should not be generated for trivial properties
+        // as the class will use direct field access instead
+        if (accessor != null && accessor.isSetter() && Visibilities.isPrivate(descriptor.getSetter().getVisibility())) {
+            return !isDefaultAccessor;
+        }
+
         return true;
     }
 
diff --git a/compiler/testData/codegen/dumpDeclarations/classMembers.json b/compiler/testData/codegen/dumpDeclarations/classMembers.json
index e959e87e511..a821b9882c0 100644
--- a/compiler/testData/codegen/dumpDeclarations/classMembers.json
+++ b/compiler/testData/codegen/dumpDeclarations/classMembers.json
@@ -40,13 +40,11 @@
 			{"visibility": "internal",	"declaration": "final fun <set-internalVar>(<set-?>: kotlin.String): kotlin.Unit", "name": "setInternalVar$test_module", "desc": "(Ljava/lang/String;)V"},
 			{"visibility": "internal",	"declaration": "final lateinit var internalVarPrivateSet: kotlin.String", "name": "internalVarPrivateSet", "desc": "Ljava/lang/String;"},
 			{"visibility": "internal",	"declaration": "final fun <get-internalVarPrivateSet>(): kotlin.String", "name": "getInternalVarPrivateSet$test_module", "desc": "()Ljava/lang/String;"},
-			{"visibility": "private",	"declaration": "final fun <set-internalVarPrivateSet>(<set-?>: kotlin.String): kotlin.Unit", "name": "setInternalVarPrivateSet", "desc": "(Ljava/lang/String;)V"},
 			{"visibility": "protected",	"declaration": "final lateinit var protectedVar: kotlin.String", "name": "protectedVar", "desc": "Ljava/lang/String;"},
 			{"visibility": "protected",	"declaration": "final fun <get-protectedVar>(): kotlin.String", "name": "getProtectedVar", "desc": "()Ljava/lang/String;"},
 			{"visibility": "protected",	"declaration": "final fun <set-protectedVar>(<set-?>: kotlin.String): kotlin.Unit", "name": "setProtectedVar", "desc": "(Ljava/lang/String;)V"},
 			{"visibility": "protected",	"declaration": "final lateinit var protectedVarPrivateSet: kotlin.String", "name": "protectedVarPrivateSet", "desc": "Ljava/lang/String;"},
 			{"visibility": "protected",	"declaration": "final fun <get-protectedVarPrivateSet>(): kotlin.String", "name": "getProtectedVarPrivateSet", "desc": "()Ljava/lang/String;"},
-			{"visibility": "private",	"declaration": "final fun <set-protectedVarPrivateSet>(<set-?>: kotlin.String): kotlin.Unit", "name": "setProtectedVarPrivateSet", "desc": "(Ljava/lang/String;)V"},
 			{"visibility": "private",	"declaration": "final lateinit var privateVar: kotlin.Any", "name": "privateVar", "desc": "Ljava/lang/Object;"},
 			{"visibility": "public",	"declaration": "constructor ClassWithLateinit()", "name": "<init>", "desc": "()V"}
 		]
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/PropertyGenTest.java b/compiler/tests/org/jetbrains/kotlin/codegen/PropertyGenTest.java
index 579b45cb27f..7e318263780 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/PropertyGenTest.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/PropertyGenTest.java
@@ -124,9 +124,10 @@ public class PropertyGenTest extends CodegenTestCase {
         getFoo.setAccessible(true);
         assertTrue((getFoo.getModifiers() & Modifier.PROTECTED) != 0);
         assertEquals(349, getFoo.invoke(instance));
-        Method setFoo = findDeclaredMethodByName(aClass, "setFoo");
-        setFoo.setAccessible(true);
-        assertTrue((setFoo.getModifiers() & Modifier.PRIVATE) != 0);
+        // See KT-20344
+        // Method setFoo = findDeclaredMethodByName(aClass, "setFoo");
+        // setFoo.setAccessible(true);
+        // assertTrue((setFoo.getModifiers() & Modifier.PRIVATE) != 0);
         Method setter = findDeclaredMethodByName(aClass, "setter");
         setter.invoke(instance);
         assertEquals(610, getFoo.invoke(instance));
@@ -247,4 +248,12 @@ public class PropertyGenTest extends CodegenTestCase {
         assertNull("Property should not have a getter", findDeclaredMethodByNameOrNull(c, "getVarNoAccessors"));
         assertNull("Property should not have a setter", findDeclaredMethodByNameOrNull(c, "setVarNoAccessors"));
     }
+
+    // Properties with trivial private setters should not generate their setters since
+    // the class will use direct field access instead for these properties.
+    public void testKt20344() throws Exception {
+        loadText("class Foo { public lateinit var x: String private set }");
+        Class<?> aClass = generateClass("Foo");
+        assertNull("Property should not have generated setter", findDeclaredMethodByNameOrNull(aClass, "setX"));
+    }
 }