diff --git a/board/safety/safety_elm327.h b/board/safety/safety_elm327.h
index ce405b47675f11..e5ac049500b6dc 100644
--- a/board/safety/safety_elm327.h
+++ b/board/safety/safety_elm327.h
@@ -11,8 +11,8 @@ static int elm327_tx_hook(CAN_FIFOMailBox_TypeDef *to_send) {
 
   //Check valid 29 bit send addresses for ISO 15765-4
   //Check valid 11 bit send addresses for ISO 15765-4
-  if ((addr != 0x18DB33F1) && ((addr & 0x1FFF00FF) != 0x18DA00F1) &&
-      ((addr != 0x7DF) && ((addr & 0x7F8) != 0x7E0))) {
+  if ((addr != 0x18DB33F1) && ((addr & 0xFFFF00FF) != 0x18DA00F1) &&
+      ((addr != 0x7DF) && ((addr & 0xFFFFFFF8) != 0x7E0))) {
     tx = 0;
   }
   return tx;