diff --git a/clang/tools/libclang/CXCursor.cpp b/clang/tools/libclang/CXCursor.cpp
index b5682055b9e3..2cdb71bb0224 100644
--- a/clang/tools/libclang/CXCursor.cpp
+++ b/clang/tools/libclang/CXCursor.cpp
@@ -1045,7 +1045,7 @@ unsigned clang_CXCursorSet_contains(CXCursorSet set, CXCursor cursor) {
   CXCursorSet_Impl *setImpl = unpackCXCursorSet(set);
   if (!setImpl)
     return 0;
-  return setImpl->find(cursor) == setImpl->end();
+  return setImpl->find(cursor) != setImpl->end();
 }
 
 unsigned clang_CXCursorSet_insert(CXCursorSet set, CXCursor cursor) {