diff --git a/java/java-psi-api/src/com/intellij/psi/PsiWildcardType.java b/java/java-psi-api/src/com/intellij/psi/PsiWildcardType.java
index d6518104b014..71fdd0b79383 100644
--- a/java/java-psi-api/src/com/intellij/psi/PsiWildcardType.java
+++ b/java/java-psi-api/src/com/intellij/psi/PsiWildcardType.java
@@ -66,12 +66,14 @@ public class PsiWildcardType extends PsiType.Stub {
   @NotNull
   public static PsiWildcardType createExtends(@NotNull PsiManager manager, @NotNull PsiType bound) {
     LOG.assertTrue(!(bound instanceof PsiWildcardType));
+    LOG.assertTrue(bound != PsiType.NULL);
     return new PsiWildcardType(manager, true, bound);
   }
 
   @NotNull
   public static PsiWildcardType createSuper(@NotNull PsiManager manager, @NotNull PsiType bound) {
     LOG.assertTrue(!(bound instanceof PsiWildcardType));
+    LOG.assertTrue(bound != PsiType.NULL);
     return new PsiWildcardType(manager, false, bound);
   }