diff --git a/java/java-impl/src/com/intellij/codeInsight/generation/surroundWith/JavaWithCastSurrounder.java b/java/java-impl/src/com/intellij/codeInsight/generation/surroundWith/JavaWithCastSurrounder.java
index 55e893884f5a..90263c4eda55 100644
--- a/java/java-impl/src/com/intellij/codeInsight/generation/surroundWith/JavaWithCastSurrounder.java
+++ b/java/java-impl/src/com/intellij/codeInsight/generation/surroundWith/JavaWithCastSurrounder.java
@@ -40,6 +40,7 @@ class JavaWithCastSurrounder extends JavaExpressionSurrounder {
   }
 
   public TextRange surroundExpression(final Project project, final Editor editor, PsiExpression expr) throws IncorrectOperationException {
+    assert expr.isValid();
     PsiType[] types = GuessManager.getInstance(project).guessTypeToCast(expr);
     final Template template = generateTemplate(project, expr.getText(), types);
     TextRange range = expr.getTextRange();
diff --git a/java/java-impl/src/com/intellij/codeInsight/guess/impl/GuessManagerImpl.java b/java/java-impl/src/com/intellij/codeInsight/guess/impl/GuessManagerImpl.java
index 54b0ba98adfa..98bebf4b31b3 100644
--- a/java/java-impl/src/com/intellij/codeInsight/guess/impl/GuessManagerImpl.java
+++ b/java/java-impl/src/com/intellij/codeInsight/guess/impl/GuessManagerImpl.java
@@ -162,6 +162,7 @@ public class GuessManagerImpl extends GuessManager {
   }
 
   private static Map<PsiExpression, PsiType> getAllTypeCasts(PsiExpression forPlace) {
+    assert forPlace.isValid();
     final int start = forPlace.getTextRange().getStartOffset();
     final Map<PsiExpression, PsiType> allCasts = new THashMap<PsiExpression, PsiType>(ExpressionTypeMemoryState.EXPRESSION_HASHING_STRATEGY);
     getTopmostBlock(forPlace).accept(new JavaRecursiveElementWalkingVisitor() {
@@ -198,6 +199,7 @@ public class GuessManagerImpl extends GuessManager {
   }
 
   private static PsiElement getTopmostBlock(PsiElement scope) {
+    assert scope.isValid();
     PsiElement lastScope = scope;
     while (true) {
       final PsiCodeBlock lastCodeBlock = PsiTreeUtil.getParentOfType(lastScope, PsiCodeBlock.class, true);
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/generation/surroundWith/SurroundWithHandler.java b/platform/lang-impl/src/com/intellij/codeInsight/generation/surroundWith/SurroundWithHandler.java
index 04b6707755d7..f13b6a4bded8 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/generation/surroundWith/SurroundWithHandler.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/generation/surroundWith/SurroundWithHandler.java
@@ -114,6 +114,9 @@ public class SurroundWithHandler implements CodeInsightActionHandler{
     for (SurroundDescriptor descriptor : surroundDescriptors) {
       final PsiElement[] elements = descriptor.getElementsToSurround(file, startOffset, endOffset);
       if (elements.length > 0) {
+        for (PsiElement element : elements) {
+          assert element.isValid() : descriptor;
+        }
         List<AnAction> applicable = buildSurroundActions(project, editor, file, descriptor.getSurrounders(), elements);
         if (applicable != null) {
           return applicable;