diff --git a/bin/compile b/bin/compile
index 759b941..d64817f 100755
--- a/bin/compile
+++ b/bin/compile
@@ -164,7 +164,7 @@ if [ ! $STACK = $CACHED_PYTHON_STACK ]; then
   bpwatch start uninstall_python
     puts-step "Stack changed, re-installing $PYTHON_VERSION."
     rm -fr .heroku/python
-    SKIP_INSTALL=0
+    unset SKIP_INSTALL
   bpwatch stop uninstall_python
 fi