diff --git a/functions b/functions
index 376aff05e3..bbde27d9f6 100644
--- a/functions
+++ b/functions
@@ -21,17 +21,6 @@ function function_exists {
     declare -f -F $1 > /dev/null
 }
 
-
-# Cleanup anything from /tmp on unstack
-# clean_tmp
-function cleanup_tmp {
-    local tmp_dir=${TMPDIR:-/tmp}
-
-    # see comments in pip_install
-    sudo rm -rf ${tmp_dir}/pip-build.*
-}
-
-
 # Retrieve an image from a URL and upload into Glance.
 # Uses the following variables:
 #
diff --git a/functions-common b/functions-common
index 4c61d6a8d2..6d1c6958dc 100644
--- a/functions-common
+++ b/functions-common
@@ -1509,15 +1509,6 @@ function pip_install {
         pip_mirror_opt="--use-mirrors"
     fi
 
-    # pip < 1.4 has a bug where it will use an already existing build
-    # directory unconditionally.  Say an earlier component installs
-    # foo v1.1; pip will have built foo's source in
-    # /tmp/$USER-pip-build.  Even if a later component specifies foo <
-    # 1.1, the existing extracted build will be used and cause
-    # confusing errors.  By creating unique build directories we avoid
-    # this problem. See https://github.com/pypa/pip/issues/709
-    local pip_build_tmp=$(mktemp --tmpdir -d pip-build.XXXXX)
-
     $xtrace
     $sudo_pip PIP_DOWNLOAD_CACHE=${PIP_DOWNLOAD_CACHE:-/var/cache/pip} \
         http_proxy=$http_proxy \
diff --git a/unstack.sh b/unstack.sh
index adb6dc17ca..fee608e17b 100755
--- a/unstack.sh
+++ b/unstack.sh
@@ -173,5 +173,3 @@ if [[ -n "$SCREEN" ]]; then
         screen -X -S $SESSION quit
     fi
 fi
-
-cleanup_tmp