diff --git a/main.go b/main.go
index 762e27f..5dd2e39 100644
--- a/main.go
+++ b/main.go
@@ -210,8 +210,8 @@ func readConfig(path string) error {
 			return err
 		}
 
-		if perms := permbits.FileMode(fi.Mode()); perms != 0o600 && perms != 0o400 {
-			return fmt.Errorf("permissions of %q are insecure: %s, please use 0600 or 0400", path, perms)
+		if perms := permbits.FileMode(fi.Mode()); perms != 0o600 && perms != 0o400 && perms != 0o440 {
+			return fmt.Errorf("permissions of %q are insecure: %s, please use 0600, 0440, or 0400", path, perms)
 		}
 
 		// Check to see if it's updated.