diff --git a/src-tauri/src/acp/preflight.rs b/src-tauri/src/acp/preflight.rs
index cf34df7..45ee429 100644
--- a/src-tauri/src/acp/preflight.rs
+++ b/src-tauri/src/acp/preflight.rs
@@ -48,6 +48,10 @@ pub struct PreflightResult {
     pub checks: Vec<CheckItem>,
 }
 
+pub fn clear_npm_env_cache() {
+    *NPM_ENV_CACHE.lock().unwrap() = None;
+}
+
 pub async fn run_preflight(agent_type: AgentType) -> PreflightResult {
     let meta = registry::get_agent_meta(agent_type);
     debug_assert_eq!(meta.agent_type, agent_type);
diff --git a/src-tauri/src/commands/acp.rs b/src-tauri/src/commands/acp.rs
index 17baaf8..f0e63a1 100644
--- a/src-tauri/src/commands/acp.rs
+++ b/src-tauri/src/commands/acp.rs
@@ -992,7 +992,13 @@ fn build_runtime_env_from_setting(
 }
 
 #[tauri::command]
-pub async fn acp_preflight(agent_type: AgentType) -> Result<PreflightResult, AcpError> {
+pub async fn acp_preflight(
+    agent_type: AgentType,
+    force_refresh: Option<bool>,
+) -> Result<PreflightResult, AcpError> {
+    if force_refresh.unwrap_or(false) {
+        preflight::clear_npm_env_cache();
+    }
     Ok(preflight::run_preflight(agent_type).await)
 }
 
diff --git a/src/components/settings/acp-agent-settings.tsx b/src/components/settings/acp-agent-settings.tsx
index dd4f001..4f2a54d 100644
--- a/src/components/settings/acp-agent-settings.tsx
+++ b/src/components/settings/acp-agent-settings.tsx
@@ -2388,11 +2388,12 @@ export function AcpAgentSettings() {
     }
   }, [])
 
-  const runPreflight = useCallback(async (agentType: AgentType) => {
+  const runPreflight = useCallback(
+    async (agentType: AgentType, forceRefresh?: boolean) => {
     setChecking((prev) => ({ ...prev, [agentType]: true }))
     try {
       const [resultState, versionState] = await Promise.allSettled([
-        acpPreflight(agentType),
+        acpPreflight(agentType, forceRefresh),
         acpDetectAgentLocalVersion(agentType),
       ])
 
@@ -4243,12 +4244,14 @@ export function AcpAgentSettings() {
                               })}
                               onClick={(event) => {
                                 event.stopPropagation()
-                                runPreflight(agent.agent_type).catch((err) => {
-                                  console.error(
-                                    "[Settings] single preflight failed:",
-                                    err
-                                  )
-                                })
+                                runPreflight(agent.agent_type, true).catch(
+                                  (err) => {
+                                    console.error(
+                                      "[Settings] single preflight failed:",
+                                      err
+                                    )
+                                  }
+                                )
                               }}
                             >
                               <RefreshCw className="h-3 w-3 shrink-0" />
diff --git a/src/lib/tauri.ts b/src/lib/tauri.ts
index b8769ef..c475c6c 100644
--- a/src/lib/tauri.ts
+++ b/src/lib/tauri.ts
@@ -210,9 +210,13 @@ export async function acpReorderAgents(agentTypes: AgentType[]): Promise<void> {
 }
 
 export async function acpPreflight(
-  agentType: AgentType
+  agentType: AgentType,
+  forceRefresh?: boolean
 ): Promise<PreflightResult> {
-  return invoke("acp_preflight", { agentType })
+  return invoke("acp_preflight", {
+    agentType,
+    forceRefresh: forceRefresh ?? null,
+  })
 }
 
 export async function acpListAgentSkills(params: {