diff --git a/hacking/env-setup b/hacking/env-setup
index 78b05dd4838..d8b5b58ee5d 100755
--- a/hacking/env-setup
+++ b/hacking/env-setup
@@ -17,10 +17,10 @@ PREFIX_PYTHONPATH="$ANSIBLE_HOME/lib"
 PREFIX_PATH="$ANSIBLE_HOME/bin"
 PREFIX_MANPATH="$ANSIBLE_HOME/docs/man"
 
-export PYTHONPATH=$PREFIX_PYTHONPATH:$PYTHONPATH
-export PATH=$PREFIX_PATH:$PATH
+[[ $PYTHONPATH != ${PREFIX_PYTHONPATH}* ]] && export PYTHONPATH=$PREFIX_PYTHONPATH:$PYTHONPATH
+[[ $PATH != ${PREFIX_PATH}* ]] && export PATH=$PREFIX_PATH:$PATH
 export ANSIBLE_LIBRARY="$ANSIBLE_HOME/library"
-export MANPATH=$PREFIX_MANPATH:$MANPATH
+[[ $MANPATH != ${PREFIX_MANPATH}* ]] && export MANPATH=$PREFIX_MANPATH:$MANPATH
 
 # Print out values unless -q is set