diff --git a/lib/Serialization/Module.cpp b/lib/Serialization/Module.cpp
index 6f2a3c2..6c48a41 100644
--- a/lib/Serialization/Module.cpp
+++ b/lib/Serialization/Module.cpp
@@ -21,7 +21,7 @@
 using namespace reader;
 
 ModuleFile::ModuleFile(ModuleKind Kind, unsigned Generation)
-  : Kind(Kind), File(nullptr), DirectlyImported(false),
+  : Kind(Kind), File(nullptr), Signature(0), DirectlyImported(false),
     Generation(Generation), SizeInBits(0),
     LocalNumSLocEntries(0), SLocEntryBaseID(0),
     SLocEntryBaseOffset(0), SLocEntryOffsets(nullptr),