diff --git a/common/error.go b/common/error.go
index 1d53f7e..b86ce38 100644
--- a/common/error.go
+++ b/common/error.go
@@ -25,6 +25,7 @@ var (
     ErrConnection       = errors.New("Connection error.")
     ErrNoActiveAgent    = errors.New("No active agent.")
     ErrExecTimeOut      = errors.New("Executing time out.")
+    ErrUnknown            = errors.New("Unknown error.")
 )
 func DisablePanic() {recover()}
 
diff --git a/worker/worker.go b/worker/worker.go
index 708a7f2..5d25b42 100644
--- a/worker/worker.go
+++ b/worker/worker.go
@@ -237,6 +237,15 @@ func (worker *Worker) SetId(id string) {
 
 // Execute the job. And send back the result.
 func (worker *Worker) exec(job *Job) (err error) {
+    defer func() {
+        if r := recover(); r != nil {
+            if e, ok := r.(error); ok {
+                err = e
+            } else {
+                err = common.ErrUnknown
+            }
+        }
+    } ()
     if worker.limit != nil {
         <-worker.limit
         defer func() {