diff --git a/bin/steps/safety b/bin/steps/safety
index 6cab98310c4d870213abb30cc69d334c7bde18f2..a1941e22d269975cd1c64bb26e65d5b98634357e 100755
--- a/bin/steps/safety
+++ b/bin/steps/safety
@@ -3,7 +3,7 @@ source $BIN_DIR/utils
 
 set +e
 
-    $tmpfile = $(mktemp)
+    tmpfile=$(mktemp /tmp/heroku-buildpack.XXXXX)
     /app/.heroku/python/bin/python $ROOT_DIR/vendor/safety.zip 2>&1 > $tmpfile
 
     if [[ $? != 0 ]]; then