diff --git a/.github/workflows/build_ubuntu-22.04.sh b/.github/workflows/build_ubuntu-22.04.sh
index a190d641f4c..67f59fe822b 100755
--- a/.github/workflows/build_ubuntu-22.04.sh
+++ b/.github/workflows/build_ubuntu-22.04.sh
@@ -21,7 +21,7 @@ fi
 # errors out. This may be removed with upgraded configure.in file.
 makecmd="make"
 if [[ "$#" -eq 2 ]]; then
-    makecmd="make CFLAGS='$CFLAGS -isystem/usr/include $2' CXXFLAGS='$CXXFLAGS -isystem/usr/include $2'"
+    makecmd="make CFLAGS='$CFLAGS -isystem/usr/include/gdal $2 $3' CXXFLAGS='$CXXFLAGS -isystem/usr/include/gdal $2 $3'"
 fi
 
 # non-existent variables as an errors
diff --git a/.github/workflows/gcc.yml b/.github/workflows/gcc.yml
index 9518ff9aeed..dfaae0f5e83 100644
--- a/.github/workflows/gcc.yml
+++ b/.github/workflows/gcc.yml
@@ -58,4 +58,4 @@ jobs:
           # TODO: -pedantic-errors here won't compile
           CXXFLAGS: -std=${{ matrix.cpp }} -fPIC -Wall -Wextra
           # CPPFLAGS: -isystem/usr/include
-        run: .github/workflows/build_ubuntu-22.04.sh $HOME/install -Wpedantic
+        run: .github/workflows/build_ubuntu-22.04.sh $HOME/install -Wpedantic -Werror