diff --git a/library/bme680/constants.py b/library/bme680/constants.py
index 0ae7a94..78b4b30 100644
--- a/library/bme680/constants.py
+++ b/library/bme680/constants.py
@@ -121,6 +121,10 @@
 RUN_GAS_DISABLE = 0
 RUN_GAS_ENABLE = 1
 
+# Gas heater enable and disable settings
+GAS_HEAT_ENABLE = 0
+GAS_HEAT_DISABLE = 1
+
 # Buffer length macro declaration
 TMP_BUFFER_LENGTH = 40
 REG_BUFFER_LENGTH = 6