diff --git a/build_wasm.sh b/build_wasm.sh
index 02ffaa5..132812c 100755
--- a/build_wasm.sh
+++ b/build_wasm.sh
@@ -9,11 +9,13 @@ else
 	cargo build --lib --target wasm32-unknown-unknown --$PROFILE || exit 1
 fi
 
-# Apply wasm-bindgen
-wasm-bindgen --target no-modules target/wasm32-unknown-unknown/$PROFILE/opentally.wasm --out-dir html --no-typescript
-
-# Apply Asyncify
-MANGLED=$(wasm-dis html/opentally_bg.wasm | grep '(import "wbg" "__wbg_getuserinput_' | awk '{print $3;}' | tr -d '"')
-wasm-opt -O2 --asyncify --pass-arg asyncify-imports@wbg.$MANGLED html/opentally_bg.wasm -o html/opentally_async.wasm
-
-rm html/opentally_bg.wasm
+if [ target/wasm32-unknown-unknown/$PROFILE/opentally.wasm -nt html/opentally_async.wasm ]; then
+	# Apply wasm-bindgen
+	wasm-bindgen --target no-modules target/wasm32-unknown-unknown/$PROFILE/opentally.wasm --out-dir html --no-typescript
+	
+	# Apply Asyncify
+	MANGLED=$(wasm-dis html/opentally_bg.wasm | grep '(import "wbg" "__wbg_getuserinput_' | awk '{print $3;}' | tr -d '"')
+	wasm-opt -O2 --asyncify --pass-arg asyncify-imports@wbg.$MANGLED html/opentally_bg.wasm -o html/opentally_async.wasm
+	
+	rm html/opentally_bg.wasm
+fi