diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index fd44bcd8..4a888d3e 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -1,5 +1,9 @@
 name: check
-on: [push,pull_request]
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
 jobs:
   build:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/image.yml b/.github/workflows/image.yml
index 03a055a7..71c917fd 100644
--- a/.github/workflows/image.yml
+++ b/.github/workflows/image.yml
@@ -19,7 +19,7 @@ jobs:
 
       - name: Build image
         run: |
-          IMAGE_ID=docker.pkg.github.com/${{ github.repository }}:${{ github.branch }}
+          IMAGE_ID=docker.pkg.github.com/${{ github.repository }}/build:${GITHUB_REF#refs/heads/}
           docker build . -f Dockerfile --tag $IMAGE_ID
           docker push $IMAGE_ID
           echo Pushed new build image $IMAGE_ID
diff --git a/debian-bootstrap.sh b/debian-bootstrap.sh
index ca1d5838..ebcfbc08 100755
--- a/debian-bootstrap.sh
+++ b/debian-bootstrap.sh
@@ -301,19 +301,6 @@ wget -qO - https://packages.confluent.io/deb/5.2/archive.key | apt-key add -
 add-apt-repository "deb https://packages.confluent.io/deb/5.2 stable main"
 apt-get update && apt install -y librdkafka-dev
 
-# Install binaryen
-curl -L https://github.com/WebAssembly/binaryen/archive/version_94.tar.gz | tar xz -C /tmp
-pushd /tmp/binaryen-version_94
-mkdir build
-cd build
-cmake \
-  -DCMAKE_BUILD_TYPE=Release \
-  -DCMAKE_INSTALL_PREFIX=/usr \
-  -G "Unix Makefiles" \
-  ..
-sudo make install
-popd
-
 Z3_VER=4.8.8
 (
   cd /usr/local/ \