diff --git a/java/java-psi-api/src/com/intellij/psi/LambdaUtil.java b/java/java-psi-api/src/com/intellij/psi/LambdaUtil.java
index 7202ecd99d3e..72b114da7399 100644
--- a/java/java-psi-api/src/com/intellij/psi/LambdaUtil.java
+++ b/java/java-psi-api/src/com/intellij/psi/LambdaUtil.java
@@ -574,7 +574,7 @@ public class LambdaUtil {
     final PsiResolveHelper resolveHelper = JavaPsiFacade.getInstance(project).getResolveHelper();
     for (PsiTypeParameter typeParameter : typeParameters) {
       final PsiType constraint = resolveHelper.getSubstitutionForTypeParameter(typeParameter, returnType, interfaceMethodReturnType, false, languageLevel);
-      if (constraint != PsiType.NULL) {
+      if (constraint != PsiType.NULL && constraint != null) {
         PsiType inferredType = null;
         final PsiClassType[] bounds = typeParameter.getExtendsListTypes();
         for (PsiClassType classTypeBound : bounds) {