diff --git a/common/environment/setup/sourcepkg.sh b/common/environment/setup/sourcepkg.sh
index 5b31f6c1f81..048096f24b2 100644
--- a/common/environment/setup/sourcepkg.sh
+++ b/common/environment/setup/sourcepkg.sh
@@ -20,6 +20,8 @@ unset -v nopie build_options build_options_default bootstrap repository reverts
 unset -v CFLAGS CXXFLAGS FFLAGS CPPFLAGS LDFLAGS LD_LIBRARY_PATH
 unset -v CC CXX CPP GCC LD AR AS RANLIB NM OBJDUMP OBJCOPY STRIP READELF PKG_CONFIG
 unset -v CMAKE_GENERATOR
+# build-helper python3
+unset -v PYPREFIX LDSHARED PYTHON_CONFIG PYTHONPATH _PYTHON_SYSCONFIGDATA_NAME
 
 # unset all $build_option_ variables
 unset -v "${!build_option_@}"