diff --git a/lib/Target/JSBackend/NaCl/ExpandI64.cpp b/lib/Target/JSBackend/NaCl/ExpandI64.cpp
index 11dddcd..e40f75c 100644
--- a/lib/Target/JSBackend/NaCl/ExpandI64.cpp
+++ b/lib/Target/JSBackend/NaCl/ExpandI64.cpp
@@ -1023,7 +1023,7 @@
   Type *i32 = Type::getInt32Ty(TheModule->getContext());
 
   SmallVector<Type*, 3> ThreeArgTypes;
-  ThreeArgTypes.push_back(i32);
+  ThreeArgTypes.push_back(Type::getInt8PtrTy(TheModule->getContext()));
   ThreeArgTypes.push_back(i32);
   ThreeArgTypes.push_back(i32);
   FunctionType *ThreeFunc = FunctionType::get(i32, ThreeArgTypes, false);