diff --git a/scripts/libpng.sh b/scripts/libpng.sh
index 454cbac..905adb2 100755
--- a/scripts/libpng.sh
+++ b/scripts/libpng.sh
@@ -9,7 +9,7 @@ until curl -L https://downloads.sourceforge.net/sourceforge/libpng/libpng-"$VERS
 mkdir build
 pushd build
 
-cmake ../libpng-"$VERSION" -DPNG_SHARED=Off -DPNG_TESTS=Off -DSKIP_INSTALL_PROGRAMS=On $CMAKE_CONFIGURE_ARGS
+cmake ../libpng-"$VERSION" -DPNG_SHARED=Off -DPNG_TESTS=Off -DSKIP_INSTALL_PROGRAMS=On --trace-expand --trace-source=CMakeLists.txt $CMAKE_CONFIGURE_ARGS
 cmake --build . --target png_static $CMAKE_BUILD_ARGS
 cmake --install . $CMAKE_BUILD_ARGS