diff --git a/crypto/o_str.c b/crypto/o_str.c
index 42b25d078..7189d1335 100644
--- a/crypto/o_str.c
+++ b/crypto/o_str.c
@@ -57,9 +57,13 @@
  */
 
 #include <ctype.h>
-#include <strings.h>
-#include "o_str.h"
 #include <openssl/e_os2.h>
+#ifdef OPENSSL_SYS_WINDOWS
+# include <string.h>
+#else
+# include <strings.h>
+#endif
+#include "o_str.h"
 
 #undef strncasecmp
 #undef strcasecmp
diff --git a/crypto/o_str.h b/crypto/o_str.h
index 744a6e27d..4a70a9e00 100644
--- a/crypto/o_str.h
+++ b/crypto/o_str.h
@@ -59,7 +59,7 @@
 #ifndef HEADER_O_STR_H
 #define HEADER_O_STR_H
 
-#include <string.h>
+#include <stddef.h>		/* to get size_t */
 
 int OPENSSL_strcasecmp(const char *str1, const char *str2);
 int OPENSSL_strncasecmp(const char *str1, const char *str2, size_t n);