diff --git a/java/java-impl/src/com/intellij/codeInsight/navigation/JavaMethodNavigationOffsetProvider.java b/java/java-impl/src/com/intellij/codeInsight/navigation/JavaMethodNavigationOffsetProvider.java
index 62d7bc1b2b03..ee84ce5c6c4a 100644
--- a/java/java-impl/src/com/intellij/codeInsight/navigation/JavaMethodNavigationOffsetProvider.java
+++ b/java/java-impl/src/com/intellij/codeInsight/navigation/JavaMethodNavigationOffsetProvider.java
@@ -24,6 +24,7 @@ import java.util.ArrayList;
  * @author yole
  */
 public class JavaMethodNavigationOffsetProvider implements MethodNavigationOffsetProvider {
+  @Override
   @Nullable
   public int[] getMethodNavigationOffsets(final PsiFile file, final int caretOffset) {
     if (file instanceof PsiJavaFile) {
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/navigation/MethodUpDownUtil.java b/platform/lang-impl/src/com/intellij/codeInsight/navigation/MethodUpDownUtil.java
index e52cd1698496..a4b2e80d854c 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/navigation/MethodUpDownUtil.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/navigation/MethodUpDownUtil.java
@@ -51,7 +51,9 @@ public class MethodUpDownUtil {
   public static int[] offsetsFromElements(final Collection<PsiElement> array) {
     TIntArrayList offsets = new TIntArrayList(array.size());
     for (PsiElement element : array) {
-      offsets.add(element.getTextOffset());
+      int offset = element.getTextOffset();
+      assert offset >= 0 : element + "; offset: " + offset;
+      offsets.add(offset);
     }
     offsets.sort();
     return offsets.toNativeArray();
diff --git a/xml/impl/src/com/intellij/codeInsight/navigation/XmlMethodNavigationOffsetProvider.java b/xml/impl/src/com/intellij/codeInsight/navigation/XmlMethodNavigationOffsetProvider.java
index d7eb4a73a1e0..136ddf84a97e 100644
--- a/xml/impl/src/com/intellij/codeInsight/navigation/XmlMethodNavigationOffsetProvider.java
+++ b/xml/impl/src/com/intellij/codeInsight/navigation/XmlMethodNavigationOffsetProvider.java
@@ -27,6 +27,7 @@ import java.util.ArrayList;
  * @author yole
  */
 public class XmlMethodNavigationOffsetProvider implements MethodNavigationOffsetProvider {
+  @Override
   public int[] getMethodNavigationOffsets(final PsiFile file, final int caretOffset) {
     if (file instanceof XmlFile) {
       PsiElement element = file;