diff --git a/packer/rpc/builder.go b/packer/rpc/builder.go
index 606c89850..6c865ee20 100644
--- a/packer/rpc/builder.go
+++ b/packer/rpc/builder.go
@@ -2,6 +2,7 @@ package rpc
 
 import (
 	"encoding/gob"
+	"fmt"
 	"github.com/mitchellh/packer/packer"
 	"log"
 	"net"