diff --git a/.github/workflows/npm-stage.yml b/.github/workflows/npm-stage.yml
index 061cbdef56..609c15b129 100644
--- a/.github/workflows/npm-stage.yml
+++ b/.github/workflows/npm-stage.yml
@@ -19,6 +19,7 @@ concurrency:
 jobs:
   stage:
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     permissions:
       contents: read
       id-token: write
diff --git a/d2js/js/ci/build.sh b/d2js/js/ci/build.sh
index 1f74c4951b..74f1804b90 100755
--- a/d2js/js/ci/build.sh
+++ b/d2js/js/ci/build.sh
@@ -15,7 +15,9 @@ if [ -n "${NPM_VERSION:-}" ]; then
   # Optimize with wasm-opt if available
   if command -v wasm-opt >/dev/null 2>&1; then
     echo "Optimizing WASM with wasm-opt..."
-    sh_c "wasm-opt -Oz --enable-bulk-memory-opt main.wasm -o main.wasm"
+    # -Oz can use quadratic memory on large Go WASM modules.
+    # https://github.com/WebAssembly/binaryen/issues/7644
+    sh_c "wasm-opt -O2 --enable-bulk-memory-opt main.wasm -o main.wasm"
   else
     echo "wasm-opt not found, skipping optimization (install with: brew install binaryen)"
   fi