diff --git a/ndk/platforms/android-9/arch-x86/include/machine/_types.h b/ndk/platforms/android-9/arch-x86/include/machine/_types.h
index e9280a5da..65892a11e 100644
--- a/ndk/platforms/android-9/arch-x86/include/machine/_types.h
+++ b/ndk/platforms/android-9/arch-x86/include/machine/_types.h
@@ -38,7 +38,7 @@
 /* the kernel defines size_t as unsigned int, but g++ wants it to be unsigned long */
 #ifndef _SIZE_T_DEFINED_
 #  define _SIZE_T_DEFINED_
-#  ifdef ANDROID
+#  ifdef __ANDROID__
      typedef unsigned int  size_t;
 #  else
      typedef unsigned long  size_t;
@@ -51,7 +51,11 @@ typedef long int       ssize_t;
 #endif
 #ifndef _PTRDIFF_T
 #define _PTRDIFF_T
-typedef long           ptrdiff_t;
+#  ifdef __ANDROID__
+     typedef int            ptrdiff_t;
+#  else
+     typedef long           ptrdiff_t;
+#  endif
 #endif
 
 #include <linux/types.h>