diff --git a/stdio-common/vfprintf.c b/stdio-common/vfprintf.c
index 6b83ba91a1..2d434ba45a 100644
--- a/stdio-common/vfprintf.c
+++ b/stdio-common/vfprintf.c
@@ -2101,7 +2101,8 @@ group_number (CHAR_T *front_ptr, CHAR_T *w, CHAR_T *rear_ptr,
 	    copy_rest:
 	      /* No further grouping to be done.  Copy the rest of the
 		 number.  */
-	      memmove (w, s, (front_ptr -s) * sizeof (CHAR_T));
+	      w -= s - front_ptr;
+	      memmove (w, front_ptr, (s - front_ptr) * sizeof (CHAR_T));
 	      break;
 	    }
 	  else if (*grouping != '\0')