diff --git a/options/auto-upgrade.nix b/options/auto-upgrade.nix
index 0809236..9a84200 100644
--- a/options/auto-upgrade.nix
+++ b/options/auto-upgrade.nix
@@ -178,7 +178,7 @@ in
                 upgrade_output="$(cat "$output_file")"
                 rm -f "$output_file"
 
-                possible_warnings="$(grep -e "^\(warning\|trace\):" <<<"$upgrade_output" || true)"
+                possible_warnings="$(grep -e "^\(warning\|trace\|evaluation warning\):" <<<"$upgrade_output" || true)"
                 if [ "$possible_warnings" != "" ] ; then
                     send_email=yes
                     email_subject_additions="$email_subject_additions with warnings"