diff --git a/src/js/challenge.js b/src/js/challenge.js
index fc29ba6..1c1492e 100644
--- a/src/js/challenge.js
+++ b/src/js/challenge.js
@@ -156,7 +156,7 @@ const powFinished = new Promise((resolve) => {
 			}
 		});
 
-		if (argon2 && !wasmSupported) {
+		if (mode === "argon2" && !wasmSupported) {
 			return insertError(__("Browser does not support WebAssembly."));
 		}
 		const powOpts = {