diff --git a/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/SandboxManager.java b/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/SandboxManager.java
index 7c0e04ceb..aeb55f12b 100644
--- a/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/SandboxManager.java
+++ b/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/SandboxManager.java
@@ -103,6 +103,10 @@ public SandboxAcquireResult acquire(
                                 "[sandbox] Priority 3: resuming from persisted state (scope={})",
                                 scopeKey.get());
                         SandboxState state = client.deserializeState(stateJson.get());
+                        // Overwrite stale WorkspaceSpec with current application config
+                        if (sandboxContext.getWorkspaceSpec() != null) {
+                            state.setWorkspaceSpec(sandboxContext.getWorkspaceSpec().copy());
+                        }
                         Sandbox sandbox = client.resume(state);
                         return SandboxAcquireResult.selfManaged(sandbox, lease);
                     }