diff --git a/src/stdlib/SDL_string.c b/src/stdlib/SDL_string.c
index a3f5b3e3a..ab339cecf 100644
--- a/src/stdlib/SDL_string.c
+++ b/src/stdlib/SDL_string.c
@@ -298,8 +298,8 @@ SDL_revcpy(void *dst, const void *src, size_t len)
 {
     char *srcp = (char *) src;
     char *dstp = (char *) dst;
-    srcp += len;
-    dstp += len;
+    srcp += len-1;
+    dstp += len-1;
     while (len--) {
         *dstp-- = *srcp--;
     }