diff --git a/.gitlab/build.sh b/.gitlab/build.sh
index 37456ce788c68d73f1cec4163891fb519e467add..0700a585ed412d4a6bfb82602dd6e272f8f12669 100755
--- a/.gitlab/build.sh
+++ b/.gitlab/build.sh
@@ -7,7 +7,7 @@ if [[ "$SYSTEM" == "linux" ]]; then
   # on linux we perform a coverage analysis
   cmake -B build -S . -DCMAKE_INSTALL_PREFIX=$PWD/install \
         -DBUILD_SHARED_LIBS=ON -DCMAKE_VERBOSE_MAKEFILE=ON \
-        -DCMAKE_C_FLAGS="-O0 -g -fPIC --coverage -Wall -fdiagnostics-show-option -fno-inline" \
+        -DCMAKE_C_FLAGS="-O0 -g -fPIC --coverage -Werror -Wall -fdiagnostics-show-option -fno-inline" \
         -DCMAKE_EXE_LINKER_FLAGS="--coverage" -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
 
 else