diff --git a/include/openssl/e_os2.h b/include/openssl/e_os2.h
index bbfb48e4babd3306711fe3b932055f0e8ddfbc5b..3e7f16cbcf32241ce8e433bae853f4ddf908cc8c 100644
--- a/include/openssl/e_os2.h
+++ b/include/openssl/e_os2.h
@@ -348,6 +348,8 @@ typedef unsigned __int64 uint64_t;
 #  else
 #   define ossl_inline
 #  endif
+# else
+#  define ossl_inline inline
 # endif
 
 #ifdef  __cplusplus