diff --git a/tools/conf/generate_sample.sh b/tools/conf/generate_sample.sh
index d42b40f81..e045ad9e8 100755
--- a/tools/conf/generate_sample.sh
+++ b/tools/conf/generate_sample.sh
@@ -17,6 +17,10 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+
+OS_VARS=$(set | sed -n '/^OS_/s/=[^=*]*$//gp' | xargs)
+[ "$OS_VARS" ] && eval "unset \$OS_VARS"
+
 FILES=$(find ceilometer -type f -name "*.py" ! -path "ceilometer/tests/*" -exec \
     grep -l "Opt(" {} \; | sort -u)