diff --git a/clang/lib/Basic/Module.cpp b/clang/lib/Basic/Module.cpp
index 7308665..1a48a6c 100644
--- a/clang/lib/Basic/Module.cpp
+++ b/clang/lib/Basic/Module.cpp
@@ -27,7 +27,7 @@
 Module::Module(StringRef Name, SourceLocation DefinitionLoc, Module *Parent,
                bool IsFramework, bool IsExplicit, unsigned VisibilityID)
     : Name(Name), DefinitionLoc(DefinitionLoc), Parent(Parent), Directory(),
-      Umbrella(), ASTFile(nullptr), VisibilityID(VisibilityID),
+      Umbrella(), Signature(0), ASTFile(nullptr), VisibilityID(VisibilityID),
       IsMissingRequirement(false), IsAvailable(true), IsFromModuleFile(false),
       IsFramework(IsFramework), IsExplicit(IsExplicit), IsSystem(false),
       IsExternC(false), IsInferred(false), InferSubmodules(false),