diff --git a/clang/lib/Serialization/GlobalModuleIndex.cpp b/clang/lib/Serialization/GlobalModuleIndex.cpp
index f43fbac..121478c 100644
--- a/clang/lib/Serialization/GlobalModuleIndex.cpp
+++ b/clang/lib/Serialization/GlobalModuleIndex.cpp
@@ -591,6 +591,10 @@
         off_t StoredSize = (off_t)Record[Idx++];
         time_t StoredModTime = (time_t)Record[Idx++];
 
+        // Skip the stored signature.
+        // FIXME: we could read the signature out of the import and validate it.
+        Idx++;
+
         // Retrieve the imported file name.
         unsigned Length = Record[Idx++];
         SmallString<128> ImportedFile(Record.begin() + Idx,