diff --git a/idea/src/org/jetbrains/kotlin/idea/inspections/collections/SimplifiableCallChainInspection.kt b/idea/src/org/jetbrains/kotlin/idea/inspections/collections/SimplifiableCallChainInspection.kt
index 262e02bc84e..9b41d22e0da 100644
--- a/idea/src/org/jetbrains/kotlin/idea/inspections/collections/SimplifiableCallChainInspection.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/inspections/collections/SimplifiableCallChainInspection.kt
@@ -59,9 +59,10 @@ class SimplifiableCallChainInspection : AbstractKotlinInspection() {
 
                     // Do not apply on maps due to lack of relevant stdlib functions
                     val firstReceiverType = firstResolvedCall.extensionReceiver?.type
-                    if (firstReceiverType != null) {
-                        val mapType = builtIns.map.defaultType
-                        if (firstReceiverType.isSubtypeOf(mapType)) return
+                    val firstReceiverRawType = firstReceiverType?.constructor?.declarationDescriptor?.defaultType
+                    if (firstReceiverRawType != null) {
+                        if (firstReceiverRawType.isSubtypeOf(builtIns.map.defaultType) ||
+                            firstReceiverRawType.isSubtypeOf(builtIns.mutableMap.defaultType)) return
                     }
 
                     // Do not apply for lambdas with return inside
diff --git a/idea/testData/inspectionsLocal/collections/simplifiableCallChain/joinToStringOnMap.kt b/idea/testData/inspectionsLocal/collections/simplifiableCallChain/joinToStringOnMap.kt
new file mode 100644
index 00000000000..935e6ae0b03
--- /dev/null
+++ b/idea/testData/inspectionsLocal/collections/simplifiableCallChain/joinToStringOnMap.kt
@@ -0,0 +1,5 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+val data = mutableMapOf<String, String>()
+val result = data.<caret>map { "${it.key}: ${it.value}" }.joinToString("\n")
\ No newline at end of file
diff --git a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
index 768de1e8144..028e4fbfef0 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
@@ -232,6 +232,12 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("joinToStringOnMap.kt")
+            public void testJoinToStringOnMap() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/collections/simplifiableCallChain/joinToStringOnMap.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("joinToStringViaBuilder.kt")
             public void testJoinToStringViaBuilder() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/collections/simplifiableCallChain/joinToStringViaBuilder.kt");