diff --git a/src/gen_dispatch.py b/src/gen_dispatch.py
index d0cb89a..b3cead6 100755
--- a/src/gen_dispatch.py
+++ b/src/gen_dispatch.py
@@ -501,8 +501,8 @@ class Generator(object):
             self.outln('typedef uint32_t khronos_uint32_t;')
             self.outln('typedef uint64_t khronos_uint64_t;')
             self.outln('typedef float khronos_float_t;')
-            self.outln('typedef intptr_t khronos_intptr_t;')
-            self.outln('typedef ptrdiff_t khronos_ssize_t;')
+            self.outln('typedef long khronos_intptr_t;')
+            self.outln('typedef long khronos_ssize_t;')
             self.outln('typedef unsigned long khronos_usize_t;')
             self.outln('typedef uint64_t khronos_utime_nanoseconds_t;')
             self.outln('typedef int64_t khronos_stime_nanoseconds_t;')