diff --git a/Godeps/Godeps.json b/Godeps/Godeps.json
index a8d748d84..ff498ed57 100644
--- a/Godeps/Godeps.json
+++ b/Godeps/Godeps.json
@@ -329,7 +329,7 @@
 		},
 		{
 			"ImportPath": "github.com/packer-community/winrmcp/winrmcp",
-			"Rev": "3d184cea22ee1c41ec1697e0d830ff0c78f7ea97"
+			"Rev": "f1bcf36a69fa2945e65dd099eee11b560fbd3346"
 		},
 		{
 			"ImportPath": "github.com/pierrec/lz4",
diff --git a/communicator/winrm/communicator.go b/communicator/winrm/communicator.go
index f16721aa4..902211bd2 100644
--- a/communicator/winrm/communicator.go
+++ b/communicator/winrm/communicator.go
@@ -41,6 +41,11 @@ func New(config *Config) (*Communicator, error) {
 
 	// Create the client
 	params := winrm.DefaultParameters()
+
+	if config.TransportDecorator != nil {
+		params.TransportDecorator = config.TransportDecorator
+	}
+
 	params.Timeout = formatDuration(config.Timeout)
 	client, err := winrm.NewClientWithParameters(
 		endpoint, config.Username, config.Password, params)
@@ -155,5 +160,6 @@ func (c *Communicator) newCopyClient() (*winrmcp.Winrmcp, error) {
 		Insecure:              c.config.Insecure,
 		OperationTimeout:      c.config.Timeout,
 		MaxOperationsPerShell: 15, // lowest common denominator
+		TransportDecorator:    c.config.TransportDecorator,
 	})
 }
diff --git a/communicator/winrm/config.go b/communicator/winrm/config.go
index a1874bf26..f9c989028 100644
--- a/communicator/winrm/config.go
+++ b/communicator/winrm/config.go
@@ -1,16 +1,18 @@
 package winrm
 
 import (
+	"net/http"
 	"time"
 )
 
 // Config is used to configure the WinRM connection
 type Config struct {
-	Host     string
-	Port     int
-	Username string
-	Password string
-	Timeout  time.Duration
-	Https    bool
-	Insecure bool
+	Host               string
+	Port               int
+	Username           string
+	Password           string
+	Timeout            time.Duration
+	Https              bool
+	Insecure           bool
+	TransportDecorator func(*http.Transport) http.RoundTripper
 }
diff --git a/helper/communicator/config.go b/helper/communicator/config.go
index 81d347e92..ad90d5e9c 100644
--- a/helper/communicator/config.go
+++ b/helper/communicator/config.go
@@ -3,6 +3,7 @@ package communicator
 import (
 	"errors"
 	"fmt"
+	"net/http"
 	"os"
 	"time"
 
@@ -32,13 +33,14 @@ type Config struct {
 	SSHFileTransferMethod string        `mapstructure:"ssh_file_transfer_method"`
 
 	// WinRM
-	WinRMUser     string        `mapstructure:"winrm_username"`
-	WinRMPassword string        `mapstructure:"winrm_password"`
-	WinRMHost     string        `mapstructure:"winrm_host"`
-	WinRMPort     int           `mapstructure:"winrm_port"`
-	WinRMTimeout  time.Duration `mapstructure:"winrm_timeout"`
-	WinRMUseSSL   bool          `mapstructure:"winrm_use_ssl"`
-	WinRMInsecure bool          `mapstructure:"winrm_insecure"`
+	WinRMUser               string        `mapstructure:"winrm_username"`
+	WinRMPassword           string        `mapstructure:"winrm_password"`
+	WinRMHost               string        `mapstructure:"winrm_host"`
+	WinRMPort               int           `mapstructure:"winrm_port"`
+	WinRMTimeout            time.Duration `mapstructure:"winrm_timeout"`
+	WinRMUseSSL             bool          `mapstructure:"winrm_use_ssl"`
+	WinRMInsecure           bool          `mapstructure:"winrm_insecure"`
+	WinRMTransportDecorator func(*http.Transport) http.RoundTripper
 }
 
 // Port returns the port that will be used for access based on config.
diff --git a/helper/communicator/step_connect_winrm.go b/helper/communicator/step_connect_winrm.go
index 26f4536ef..49936ad7b 100644
--- a/helper/communicator/step_connect_winrm.go
+++ b/helper/communicator/step_connect_winrm.go
@@ -124,13 +124,14 @@ func (s *StepConnectWinRM) waitForWinRM(state multistep.StateBag, cancel <-chan
 
 		log.Println("[INFO] Attempting WinRM connection...")
 		comm, err = winrm.New(&winrm.Config{
-			Host:     host,
-			Port:     port,
-			Username: user,
-			Password: password,
-			Timeout:  s.Config.WinRMTimeout,
-			Https:    s.Config.WinRMUseSSL,
-			Insecure: s.Config.WinRMInsecure,
+			Host:               host,
+			Port:               port,
+			Username:           user,
+			Password:           password,
+			Timeout:            s.Config.WinRMTimeout,
+			Https:              s.Config.WinRMUseSSL,
+			Insecure:           s.Config.WinRMInsecure,
+			TransportDecorator: s.Config.WinRMTransportDecorator,
 		})
 		if err != nil {
 			log.Printf("[ERROR] WinRM connection err: %s", err)