diff --git a/.github/workflows/linux.bash b/.github/workflows/linux.bash
index 6c4240d1a..75883cc91 100755
--- a/.github/workflows/linux.bash
+++ b/.github/workflows/linux.bash
@@ -101,6 +101,7 @@ cd /icinga2/build
 
 cmake \
   -GNinja \
+  -DCMAKE_CXX_FLAGS=-Werror \
   -DCMAKE_BUILD_TYPE=RelWithDebInfo \
   -DICINGA2_UNITY_BUILD=ON \
   -DUSE_SYSTEMD=ON \