diff --git a/clang/include/clang/Frontend/FrontendAction.h b/clang/include/clang/Frontend/FrontendAction.h
index 773543ac06a5..f659b2f42e91 100644
--- a/clang/include/clang/Frontend/FrontendAction.h
+++ b/clang/include/clang/Frontend/FrontendAction.h
@@ -130,7 +130,7 @@ public:
   }
 
   ASTUnit &getCurrentASTUnit() const {
-    assert(!CurrentASTUnit && "No current AST unit!");
+    assert(CurrentASTUnit && "No current AST unit!");
     return *CurrentASTUnit;
   }