diff --git a/.github/workflows/linux-builds.yml b/.github/workflows/linux-builds.yml
index eae7e003..caa6b3a1 100644
--- a/.github/workflows/linux-builds.yml
+++ b/.github/workflows/linux-builds.yml
@@ -53,9 +53,13 @@ jobs:
       # Note: $GITHUB_WORKSPACE is distinct from ${{runner.workspace}}.
       #       This is important
       run: |
-        cmake -Bbuild -H$GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=${{matrix.build_type}} \
-              -DCMAKE_CXX_STANDARD=${{matrix.std}} -DCATCH_DEVELOPMENT_BUILD=ON \
-              -DCATCH_BUILD_SURROGATES=${{matrix.surrogates}} -G Ninja
+        cmake -Bbuild -H$GITHUB_WORKSPACE \
+              -DCMAKE_BUILD_TYPE=${{matrix.build_type}} \
+              -DCMAKE_CXX_STANDARD=${{matrix.std}} \
+              -DCMAKE_CXX_EXTENSIONS=OFF \
+              -DCATCH_DEVELOPMENT_BUILD=ON \
+              -DCATCH_BUILD_SURROGATES=${{matrix.surrogates}} \
+              -G Ninja
 
     - name: Build tests + lib
       working-directory: ${{runner.workspace}}/build