diff --git a/debian/combo.init b/debian/combo.init
index a354af6d..102b4838 100644
--- a/debian/combo.init
+++ b/debian/combo.init
@@ -119,13 +119,13 @@ do_reload() {
 
 do_migrate() {
     log_action_msg "Applying migrations (migrate_schemas).."
-    su $USER -p -c "$MANAGE_SCRIPT migrate_schemas"
+    su $USER -s /bin/sh -p -c "$MANAGE_SCRIPT migrate_schemas"
     log_action_msg "done"
 }
 
 do_collectstatic() {
     log_action_msg "Collect static files (collectstatic).."
-    su $USER -p -c "$MANAGE_SCRIPT collectstatic --noinput"
+    su $USER -s /bin/sh -p -c "$MANAGE_SCRIPT collectstatic --noinput"
     log_action_msg "done"
 }