diff --git a/c/swap.c b/c/swap.c
index 657ae9d..c646855 100644
--- a/c/swap.c
+++ b/c/swap.c
@@ -3,7 +3,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-void swap_loop(char* restrict a, char* restrict b, size_t len) {
+void swap_loop(char* __restrict a, char* __restrict b, size_t len) {
     while (len--) {
         char tmp = *a;
         *a++     = *b;
@@ -11,7 +11,7 @@
     };
 }
 
-void swap_malloc(char* restrict a, char* restrict b, size_t len) {
+void swap_malloc(char* __restrict a, char* __restrict b, size_t len) {
     char *temp = malloc(len);
     memmove(temp,a,len);
     memmove(a,b,len);
@@ -19,7 +19,7 @@
     free(temp);
 }
 
-void swap_alloca(char* restrict a, char* restrict b, size_t len) {
+void swap_alloca(char* __restrict a, char* __restrict b, size_t len) {
     char temp[len];
     memmove(temp,a,len);
     memmove(a,b,len);