diff --git a/src/agents/skills/plugin-skills.ts b/src/agents/skills/plugin-skills.ts
index c3e7999fe..90c8711cd 100644
--- a/src/agents/skills/plugin-skills.ts
+++ b/src/agents/skills/plugin-skills.ts
@@ -12,10 +12,10 @@ import { loadPluginManifestRegistry } from "../../plugins/manifest-registry.js";
 const log = createSubsystemLogger("skills");
 
 export function resolvePluginSkillDirs(params: {
-  workspaceDir: string;
+  workspaceDir: string | undefined;
   config?: OpenClawConfig;
 }): string[] {
-  const workspaceDir = params.workspaceDir.trim();
+  const workspaceDir = (params.workspaceDir ?? "").trim();
   if (!workspaceDir) {
     return [];
   }