diff --git a/platform/avr-rss2/dev/co2_sa_kxx-sensor.c b/platform/avr-rss2/dev/co2_sa_kxx-sensor.c
index 1866c0f2f..564f8c011 100644
--- a/platform/avr-rss2/dev/co2_sa_kxx-sensor.c
+++ b/platform/avr-rss2/dev/co2_sa_kxx-sensor.c
@@ -112,7 +112,7 @@ value(int var)
 
   status = i2c_readAck();
 
-  if(status & 0x01 == 0) 
+  if((status & 0x01) == 0) 
     goto err;
 
   buf[0] = i2c_readAck();