diff --git a/js/js.tests/test/org/jetbrains/k2js/test/rhino/RhinoFunctionNativeObjectResultChecker.java b/js/js.tests/test/org/jetbrains/k2js/test/rhino/RhinoFunctionNativeObjectResultChecker.java
index 59eba9537cc..198f6a5cea8 100644
--- a/js/js.tests/test/org/jetbrains/k2js/test/rhino/RhinoFunctionNativeObjectResultChecker.java
+++ b/js/js.tests/test/org/jetbrains/k2js/test/rhino/RhinoFunctionNativeObjectResultChecker.java
@@ -17,6 +17,7 @@
 package org.jetbrains.k2js.test.rhino;
 
 import org.jetbrains.annotations.Nullable;
+import org.mozilla.javascript.Context;
 import org.mozilla.javascript.NativeJavaObject;
 
 /**
@@ -33,13 +34,13 @@ public class RhinoFunctionNativeObjectResultChecker extends RhinoFunctionResultC
     }
 
     @Override
-    protected void assertResultValid(Object result) {
+    protected void assertResultValid(Object result, Context context) {
         if (result instanceof NativeJavaObject) {
             NativeJavaObject nativeJavaObject = (NativeJavaObject) result;
             Object unwrap = nativeJavaObject.unwrap();
-            super.assertResultValid(unwrap);
+            super.assertResultValid(unwrap, context);
         } else {
-            super.assertResultValid(result);
+            super.assertResultValid(result, context);
         }
     }
 }
diff --git a/js/js.tests/test/org/jetbrains/k2js/test/rhino/RhinoFunctionResultChecker.java b/js/js.tests/test/org/jetbrains/k2js/test/rhino/RhinoFunctionResultChecker.java
index 396ff1dba12..2cf3960b16d 100644
--- a/js/js.tests/test/org/jetbrains/k2js/test/rhino/RhinoFunctionResultChecker.java
+++ b/js/js.tests/test/org/jetbrains/k2js/test/rhino/RhinoFunctionResultChecker.java
@@ -44,11 +44,12 @@ public class RhinoFunctionResultChecker implements RhinoResultChecker {
     @Override
     public void runChecks(Context context, Scriptable scope) throws Exception {
         Object result = evaluateFunction(context, scope);
-        assertResultValid(result);
+        assertResultValid(result, context);
     }
 
-    protected void assertResultValid(Object result) {
-        assertEquals("Result of " + namespaceName + "." + functionName + "() is not what expected!", expectedResult, result);
+    protected void assertResultValid(Object result, Context context) {
+        String ecmaVersion = context.getLanguageVersion() == Context.VERSION_1_8 ? "ecma5" : "ecma3";
+        assertEquals("Result of " + namespaceName + "." + functionName + "() is not what expected (" + ecmaVersion + ")!", expectedResult, result);
         String report = namespaceName + "." + functionName + "() = " + Context.toString(result);
         System.out.println(report);
     }