diff --git a/src/mol-canvas3d/passes/smaa.ts b/src/mol-canvas3d/passes/smaa.ts
index 6d5f72c0febc5567626f4119b54c83a7a85d631a..763c8ecca3b6a59c000248807a10440898707eef 100644
--- a/src/mol-canvas3d/passes/smaa.ts
+++ b/src/mol-canvas3d/passes/smaa.ts
@@ -44,7 +44,7 @@ export class SmaaPass {
     }
 
     constructor(private webgl: WebGLContext, input: Texture) {
-        if (typeof HTMLImageElement === undefined) {
+        if (typeof HTMLImageElement === 'undefined') {
             if (isDebugMode) console.log(`Missing "HTMLImageElement" required for "SMAA"`);
             return;
         }