diff --git a/examples_ptx/mergeSort/keyType.h b/examples_ptx/mergeSort/keyType.h
new file mode 100644
index 00000000..82de34af
--- /dev/null
+++ b/examples_ptx/mergeSort/keyType.h
@@ -0,0 +1,3 @@
+#pragma once
+typedef float Key_t;
+typedef int   Val_t;
diff --git a/examples_ptx/mergeSort/mergeSort.cpp b/examples_ptx/mergeSort/mergeSort.cpp
index b32c995c..d21560ef 100644
--- a/examples_ptx/mergeSort/mergeSort.cpp
+++ b/examples_ptx/mergeSort/mergeSort.cpp
@@ -30,8 +30,7 @@ static inline void progressbar (unsigned int x, unsigned int n, unsigned int w =
   cout << "]\r" << flush;
 }
 
-typedef float Key_t;
-typedef int   Val_t;
+#include "keyType.h"
 struct Key
 {
   Key_t key;
diff --git a/examples_ptx/mergeSort/mergeSort.ispc b/examples_ptx/mergeSort/mergeSort.ispc
index ee7b69d8..52a94085 100644
--- a/examples_ptx/mergeSort/mergeSort.ispc
+++ b/examples_ptx/mergeSort/mergeSort.ispc
@@ -1,5 +1,4 @@
-typedef float Key_t;
-typedef int   Val_t;
+#include "keyType.h"
 
 #define SAMPLE_STRIDE programCount