diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java
index 2bf0aec03df..40af774d941 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java
@@ -3914,7 +3914,9 @@ public class ExpressionCodegen extends KtVisitor<StackValue, StackValue> impleme
 
             boolean isGetter = OperatorNameConventions.GET.equals(operationDescriptor.getName());
 
-            Callable callable = resolveToCallable(operationDescriptor, false, isGetter ? resolvedGetCall : resolvedSetCall);
+            ResolvedCall<FunctionDescriptor> resolvedCall = isGetter ? resolvedGetCall : resolvedSetCall;
+            assert resolvedCall != null : "No resolved call for " + operationDescriptor;
+            Callable callable = resolveToCallable(accessibleFunctionDescriptor(resolvedCall), false, resolvedCall);
             Callable callableMethod = resolveToCallableMethod(operationDescriptor, false);
             Type[] argumentTypes = callableMethod.getParameterTypes();
 
diff --git a/compiler/testData/codegen/box/operatorConventions/kt20387.kt b/compiler/testData/codegen/box/operatorConventions/kt20387.kt
new file mode 100644
index 00000000000..95fcaa70ec6
--- /dev/null
+++ b/compiler/testData/codegen/box/operatorConventions/kt20387.kt
@@ -0,0 +1,17 @@
+// FILE: test.kt
+import base.*
+
+class Derived : Base<Long>() {
+    inner class Inner {
+        fun foo() = this@Derived[0L]
+    }
+}
+
+fun box() = Derived().Inner().foo()
+
+// FILE: Base.kt
+package base
+
+open class Base<K> {
+    protected operator fun get(key: K) = "OK"
+}
\ No newline at end of file
diff --git a/compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java b/compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java
index bc9a65fc5f7..a8801ae0325 100644
--- a/compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java
+++ b/compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java
@@ -12194,6 +12194,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             doTest(fileName);
         }
 
+        @TestMetadata("kt20387.kt")
+        public void testKt20387() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/operatorConventions/kt20387.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt4152.kt")
         public void testKt4152() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/operatorConventions/kt4152.kt");
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java
index 30b4d0112c6..07412989dad 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java
@@ -12194,6 +12194,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest(fileName);
         }
 
+        @TestMetadata("kt20387.kt")
+        public void testKt20387() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/operatorConventions/kt20387.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt4152.kt")
         public void testKt4152() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/operatorConventions/kt4152.kt");
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java
index 8510ee1169f..b647c12016c 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java
@@ -12194,6 +12194,12 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             doTest(fileName);
         }
 
+        @TestMetadata("kt20387.kt")
+        public void testKt20387() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/operatorConventions/kt20387.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt4152.kt")
         public void testKt4152() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/operatorConventions/kt4152.kt");
diff --git a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java
index 240799a4fe4..47403e25b3b 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java
+++ b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java
@@ -13454,6 +13454,12 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             doTest(fileName);
         }
 
+        @TestMetadata("kt20387.kt")
+        public void testKt20387() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/operatorConventions/kt20387.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt4152.kt")
         public void testKt4152() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/operatorConventions/kt4152.kt");