diff --git a/llvm/include/llvm/ADT/FunctionExtras.h b/llvm/include/llvm/ADT/FunctionExtras.h
index 4cf1de488c7b..2fcbab44ff94 100644
--- a/llvm/include/llvm/ADT/FunctionExtras.h
+++ b/llvm/include/llvm/ADT/FunctionExtras.h
@@ -151,7 +151,7 @@ template <typename ReturnT, typename... ParamTs> class UniqueFunctionBase {
       void *StoragePtr;
       size_t Size;
       size_t Alignment;
-    } OutOfLineStorage;
+    } OutOfLineStorage = {};
     static_assert(
         sizeof(OutOfLineStorageT) <= InlineStorageSize,
         "Should always use all of the out-of-line storage for inline storage!");