diff --git a/lib/DebugInfo/PDB/Native/NativeTypeFunctionSig.cpp b/lib/DebugInfo/PDB/Native/NativeTypeFunctionSig.cpp
index a798bcdba79..a72c8d204c6 100644
--- a/lib/DebugInfo/PDB/Native/NativeTypeFunctionSig.cpp
+++ b/lib/DebugInfo/PDB/Native/NativeTypeFunctionSig.cpp
@@ -11,6 +11,7 @@
 
 #include "llvm/DebugInfo/CodeView/LazyRandomTypeCollection.h"
 #include "llvm/DebugInfo/PDB/Native/NativeEnumTypes.h"
+#include "llvm/DebugInfo/PDB/PDBExtras.h"
 #include "llvm/DebugInfo/PDB/Native/PDBFile.h"
 #include "llvm/DebugInfo/PDB/Native/TpiStream.h"