diff --git a/ext/standard/string.c b/ext/standard/string.c
index d8a7479d2a98..a43f64158c36 100644
--- a/ext/standard/string.c
+++ b/ext/standard/string.c
@@ -5524,7 +5524,8 @@ PHP_FUNCTION(str_repeat)
 
 		while (e<ee) {
 			l = (e-s) < (ee-e) ? (e-s) : (ee-e);
-			memmove(e, s, l);
+			/* src [s, s+l) and dst [e, e+l) cannot overlap: l <= e-s */
+			memcpy(e, s, l);
 			e += l;
 		}
 	}