diff --git a/types/mapbox-gl/index.d.ts b/types/mapbox-gl/index.d.ts
index a524e31aeb..8a80a24b83 100644
--- a/types/mapbox-gl/index.d.ts
+++ b/types/mapbox-gl/index.d.ts
@@ -32,7 +32,7 @@ declare namespace mapboxgl {
         // Lookup
         | 'at' | 'get' | 'has' | 'length'
         // Decision
-        | '!=' | '<' | '<=' | '==' | '>' | '>=' | 'all' | 'any' | 'case' | 'match'
+        | '!' | '!=' | '<' | '<=' | '==' | '>' | '>=' | 'all' | 'any' | 'case' | 'match'
         // Ramps, scales, curves
         | 'interpolate' | 'interpolate-hcl' | 'interpolate-lab' | 'step'
         // Variable binding