diff --git a/commodore/component/__init__.py b/commodore/component/__init__.py
index e5caffdf..2c3fae51 100644
--- a/commodore/component/__init__.py
+++ b/commodore/component/__init__.py
@@ -160,9 +160,9 @@ def alias_directory(self, alias: str) -> P:
         apath = self._dependency.get_component(alias)
         if not apath:
             raise ValueError(f"unknown alias {alias} for component {self.name}")
-        if alias in self._aliases:
-            return apath / self._aliases[alias][1]
-        return apath / self._sub_path
+        if alias not in self._aliases:
+            raise ValueError(f"alias {alias} for component {self.name} has not been registered")
+        return apath / self._aliases[alias][1]
 
     def alias_class_file(self, alias: str) -> P:
         return self.alias_directory(alias) / "class" / f"{self.name}.yml"