diff --git a/builder/standalone-install.sh b/builder/standalone-install.sh
index b4ac195a..08aef8d5 100755
--- a/builder/standalone-install.sh
+++ b/builder/standalone-install.sh
@@ -56,7 +56,7 @@ cd /root/catkin_ws
 catkin_make
 
 # Step 4: Run tests
-pip install --upgrade pytest
+${PYTHON} -m pip install --upgrade pytest
 cd /root/catkin_ws
 source devel/setup.bash
 catkin_make run_tests && catkin_test_results