diff --git a/lib/string.c b/lib/string.c
index 7be6f0a..064f631 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -470,7 +470,7 @@
 void *memcpy(void *dest, const void *src, size_t count)
 {
 	char *tmp = dest;
-	char *s = src;
+	const char *s = src;
 
 	while (count--)
 		*tmp++ = *s++;