diff --git a/idea/src/org/jetbrains/jet/plugin/highlighter/JetLineMarkerProvider.java b/idea/src/org/jetbrains/jet/plugin/highlighter/JetLineMarkerProvider.java
index 481c93c4415..bff8dcc2b71 100644
--- a/idea/src/org/jetbrains/jet/plugin/highlighter/JetLineMarkerProvider.java
+++ b/idea/src/org/jetbrains/jet/plugin/highlighter/JetLineMarkerProvider.java
@@ -360,7 +360,9 @@ public class JetLineMarkerProvider implements LineMarkerProvider {
 
     @Override
     public void collectSlowLineMarkers(@NotNull List<PsiElement> elements, @NotNull Collection<LineMarkerInfo> result) {
-        if (elements.isEmpty() || DumbService.getInstance(elements.get(0).getProject()).isDumb()) {
+        if (elements.isEmpty() ||
+            DumbService.getInstance(elements.get(0).getProject()).isDumb() ||
+            !JetPsiChecker.isInSourceContent(elements.get(0))) {
             return;
         }
 
diff --git a/idea/src/org/jetbrains/jet/plugin/highlighter/JetPsiChecker.java b/idea/src/org/jetbrains/jet/plugin/highlighter/JetPsiChecker.java
index ef4ce3ded11..422f4a14e9c 100644
--- a/idea/src/org/jetbrains/jet/plugin/highlighter/JetPsiChecker.java
+++ b/idea/src/org/jetbrains/jet/plugin/highlighter/JetPsiChecker.java
@@ -276,7 +276,7 @@ public class JetPsiChecker implements Annotator {
         return annotation;
     }
 
-    static boolean isInSourceContent(PsiElement element) {
+    public static boolean isInSourceContent(PsiElement element) {
         PsiFile containingFile = element.getContainingFile();
         if (containingFile == null) {
             return false;
diff --git a/idea/src/org/jetbrains/jet/plugin/search/KotlinReferencesSearcher.java b/idea/src/org/jetbrains/jet/plugin/search/KotlinReferencesSearcher.java
index b9c5c3ca203..2d64b97f2bd 100644
--- a/idea/src/org/jetbrains/jet/plugin/search/KotlinReferencesSearcher.java
+++ b/idea/src/org/jetbrains/jet/plugin/search/KotlinReferencesSearcher.java
@@ -28,6 +28,7 @@ import com.intellij.util.Processor;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.asJava.LightClassUtil;
 import org.jetbrains.jet.lang.psi.*;
+import org.jetbrains.jet.plugin.highlighter.JetPsiChecker;
 
 public class KotlinReferencesSearcher extends QueryExecutorBase<PsiReference, ReferencesSearch.SearchParameters> {
     public static void processJetClassOrObject(
@@ -50,6 +51,9 @@ public class KotlinReferencesSearcher extends QueryExecutorBase<PsiReference, Re
     @Override
     public void processQuery(@NotNull ReferencesSearch.SearchParameters queryParameters, @NotNull Processor<PsiReference> consumer) {
         PsiElement element = queryParameters.getElementToSearch();
+        if (!JetPsiChecker.isInSourceContent(element)) {
+            return;
+        }
         if (element instanceof JetClass) {
             processJetClassOrObject((JetClass) element, queryParameters);
         }