diff --git a/crypto/bn/asm/x86_64-gcc.c b/crypto/bn/asm/x86_64-gcc.c
index 85191ecb0..9381ccf42 100644
--- a/crypto/bn/asm/x86_64-gcc.c
+++ b/crypto/bn/asm/x86_64-gcc.c
@@ -1,7 +1,7 @@
 #ifdef __SUNPRO_C
 # include "../bn_asm.c"	/* kind of dirty hack for Sun Studio */
 #else
-#include <sys/types.h>
+#include <stddef.h>
 /*
  * x86_64 BIGNUM accelerator version 0.1, December 2002.
  *