diff --git a/start.sh b/start.sh
index 07cf5940a..54bfd2d0e 100755
--- a/start.sh
+++ b/start.sh
@@ -25,6 +25,12 @@ if [[ -d .stack-work-run ]]; then
     trap move-back EXIT
 fi
 
-# stack exec -- yesod devel $@
-
-yesod devel $@
+if ! [ -z "$(which yesod)" ]
+then
+  yesod devel $@
+elif ! [ -z "$(which stack)" ]
+then
+  stack exec -- yesod devel $@
+else
+  exit 1
+fi