diff --git a/.github/build-llvm.sh b/.github/build-llvm.sh
index a991e6c9d..a73121f01 100755
--- a/.github/build-llvm.sh
+++ b/.github/build-llvm.sh
@@ -1,9 +1,12 @@
 #!/bin/bash
 set -e
 
+# Install and use ninja because using the default makefiles seems to be broken
+sudo apt-get install ninja-build
+
 mkdir -p circt/llvm/build
 cd circt/llvm/build
-cmake ../llvm \
+cmake -G Ninja ../llvm \
     -DCMAKE_BUILD_TYPE=Release \
     -DLLVM_BUILD_EXAMPLES=OFF \
     -DLLVM_ENABLE_ASSERTIONS=ON \
@@ -14,4 +17,4 @@ cmake ../llvm \
     -DLLVM_OPTIMIZED_TABLEGEN=ON \
     -DLLVM_TARGETS_TO_BUILD="host"
 
-cmake --build . -- -j$(nproc)
+ninja -j$(nproc)
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3954c28cf..84ffebac6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,7 +5,7 @@ name: CI
 jobs:
   lints:
     name: Lints
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Checkout sources
         uses: actions/checkout@v2
@@ -32,7 +32,7 @@ jobs:
 
   check:
     name: Checks
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Checkout sources
         uses: actions/checkout@v2