diff --git a/.github/workflows/ci_macos.yaml b/.github/workflows/ci_macos.yaml
index f6592fcdb..6d86278c2 100644
--- a/.github/workflows/ci_macos.yaml
+++ b/.github/workflows/ci_macos.yaml
@@ -82,6 +82,7 @@ jobs:
             -B build \
             -G "Ninja" \
             -DCMAKE_BUILD_TYPE=RelWithDebInfo \
+            -DCMAKE_CXX_FLAGS="-Werror -Wno-error=deprecated-declarations" \
             -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
             -DBOOST_ROOT="${{ env.boost_path }}" \
             -DOPENSSL_ROOT_DIR="${{ env.openssl_root }}" \
@@ -99,6 +100,7 @@ jobs:
             -B build \
             -G "Ninja" \
             -DCMAKE_BUILD_TYPE=RelWithDebInfo \
+            -DCMAKE_CXX_FLAGS="-Werror -Wno-error=deprecated-declarations" \
             -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
             -DBOOST_ROOT="${{ env.boost_path }}" \
             -DOPENSSL_ROOT_DIR="${{ env.openssl_root }}" \
diff --git a/.github/workflows/ci_ubuntu.yaml b/.github/workflows/ci_ubuntu.yaml
index eb9ecfeed..5e060bb4d 100644
--- a/.github/workflows/ci_ubuntu.yaml
+++ b/.github/workflows/ci_ubuntu.yaml
@@ -68,6 +68,7 @@ jobs:
             -B build \
             -G "Ninja" \
             -DCMAKE_BUILD_TYPE=RelWithDebInfo \
+            -DCMAKE_CXX_FLAGS="-Werror -Wno-error=deprecated-declarations" \
             -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
             -DCMAKE_INSTALL_PREFIX="/usr" \
             -DTESTING=ON \
@@ -85,6 +86,7 @@ jobs:
             -B build \
             -G "Ninja" \
             -DCMAKE_BUILD_TYPE=RelWithDebInfo \
+            -DCMAKE_CXX_FLAGS="-Werror" \
             -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
             -DCMAKE_INSTALL_PREFIX="/usr" \
             -DQT6=ON \
diff --git a/.github/workflows/ci_windows.yaml b/.github/workflows/ci_windows.yaml
index ef4819b58..e31255a0e 100644
--- a/.github/workflows/ci_windows.yaml
+++ b/.github/workflows/ci_windows.yaml
@@ -108,6 +108,7 @@ jobs:
             -B build `
             -G "Ninja" `
             -DCMAKE_BUILD_TYPE=RelWithDebInfo `
+            -DCMAKE_CXX_FLAGS="/WX" `
             -DCMAKE_EXPORT_COMPILE_COMMANDS=ON `
             -DCMAKE_TOOLCHAIN_FILE="${{ env.RUNVCPKG_VCPKG_ROOT }}/scripts/buildsystems/vcpkg.cmake" `
             -DBOOST_ROOT="${{ env.boost_path }}" `