diff --git a/src/frontend/device.c b/src/frontend/device.c
index 6d44bd054..e861944cb 100644
--- a/src/frontend/device.c
+++ b/src/frontend/device.c
@@ -1246,6 +1246,7 @@ com_alter_common(wordlist *wl, int do_model)
     /* in case the altermod command comes from commandline or
        over shared library we have to provide lowercase */
     strtolower(param);
+    strtolower(dev);
 
     words = eqword->wl_next;
     /* skip next line if words is a vector */