diff --git a/.github/workflows/emscripten.yml b/.github/workflows/emscripten.yml
index 3e29fbc..b5a3ed0 100644
--- a/.github/workflows/emscripten.yml
+++ b/.github/workflows/emscripten.yml
@@ -39,7 +39,7 @@ jobs:
         ./scripts/run-ci-wasm.sh
         ls -la
     - name: Dist prep
-      run: ./dist-prep.sh
+      run: ./dist-prep.sh ${{ matrix.target }}
     - name: Artifacts
       uses: actions/upload-artifact@v3
       with:
diff --git a/dist-prep.sh b/dist-prep.sh
index 4ef59f7..9d2f6a9 100755
--- a/dist-prep.sh
+++ b/dist-prep.sh
@@ -1,6 +1,8 @@
 #!/bin/bash
 set -e
 
+build_target="$1"
+
 echoerr() { echo "$@" 1>&2; }
 
 function assertFile {
@@ -15,13 +17,33 @@ rm -rf dist/*
 
 ls -la libheif
 
-cp libheif/libheif.js dist/libheif.js
-cp libheif/COPYING dist/LICENSE
-cp libheif/libheif.wasm dist/libheif.wasm || echo wasm not found
+function copyJs() {
+  cp libheif/libheif.js dist/libheif.js
+  cp libheif/COPYING dist/LICENSE
+
+  assertFile dist/libheif.js
+  assertFile dist/LICENSE
+
+  chown $(whoami) dist/libheif.js dist/LICENSE
+}
+
+function copyWasm() {
+  copyJs
+
+  cp libheif/libheif.wasm dist/libheif.wasm
+  assertFile dist/libheif.wasm
+  chown $(whoami) dist/libheif.wasm
+}
 
-assertFile dist/libheif.js
-assertFile dist/LICENSE
+if [ "$build_target" = "js" ]
+then
+  copyJs
+elif [ "$build_target" = "wasm" ]
+then
+  copyWasm
+else
+  echo "unknown build target: $build_target"
+  exit 1
+fi
 
-chown $(whoami) dist/libheif.js dist/LICENSE
-chown $(whoami) dist/libheif.wasm || echo wasm not found
 ls -la dist