diff --git a/data/json/items/tool_armor.json b/data/json/items/tool_armor.json
index a0077170da424..f7f36182a53b6 100644
--- a/data/json/items/tool_armor.json
+++ b/data/json/items/tool_armor.json
@@ -994,6 +994,7 @@
       "SWIM_GOGGLES",
       "SUN_GLASSES",
       "RAD_PROOF",
+      "GAS_PROOF",
       "ELECTRIC_IMMUNE",
       "THERMOMETER",
       "TRADER_AVOID",