diff --git a/builder/googlecompute/config.go b/builder/googlecompute/config.go
index 6b0acac08..16ee632d6 100644
--- a/builder/googlecompute/config.go
+++ b/builder/googlecompute/config.go
@@ -426,18 +426,28 @@ func (c *Config) Prepare(raws ...interface{}) ([]string, error) {
 		}
 	}
 	if c.IAPConfig.IAPTunnelLaunchWait == 0 {
-		c.IAPConfig.IAPTunnelLaunchWait = 30
+		if c.Comm.Type == "winrm" {
+			// when starting up, WinRM can cause the tunnel to take 30 seconds
+			// before timing out
+			c.IAPConfig.IAPTunnelLaunchWait = 40
+		} else {
+			c.IAPConfig.IAPTunnelLaunchWait = 30
+		}
 	}
 
 	// Configure IAP: Update SSH config to use localhost proxy instead
 	if c.IAPConfig.IAP {
-		if c.Comm.Type == "ssh" {
-			c.Comm.SSHHost = "localhost"
-		} else {
-			err := fmt.Errorf("Error: IAP tunnel currently only implemnted for" +
-				" SSH communicator")
+		if !SupportsIAPTunnel(&c.Comm) {
+			err := fmt.Errorf("Error: IAP tunnel is not implemented for %s communicator", c.Comm.Type)
 			errs = packer.MultiErrorAppend(errs, err)
 		}
+		// These configuration values are copied early to the generic host parameter when configuring
+		// StepConnect. As such they must be set now. Ideally we would handle this as part of
+		// ApplyIAPTunnel and set them during StepStartTunnel but that means defering when the
+		// CommHost function reads the value from the configuration, perhaps pass in b.config.Comm
+		// instead of b.config.Comm.Host()?
+		c.Comm.SSHHost = "localhost"
+		c.Comm.WinRMHost = "localhost"
 	}
 
 	// Process required parameters.
@@ -541,3 +551,25 @@ func (k *CustomerEncryptionKey) ComputeType() *compute.CustomerEncryptionKey {
 		RawKey:     k.RawKey,
 	}
 }
+
+func SupportsIAPTunnel(c *communicator.Config) bool {
+	switch c.Type {
+	case "ssh", "winrm":
+		return true
+	default:
+		return false
+	}
+}
+
+func ApplyIAPTunnel(c *communicator.Config, port int) error {
+	switch c.Type {
+	case "ssh":
+		c.SSHPort = port
+		return nil
+	case "winrm":
+		c.WinRMPort = port
+		return nil
+	default:
+		return fmt.Errorf("IAP tunnel is not implemented for %s communicator", c.Type)
+	}
+}
diff --git a/builder/googlecompute/config_test.go b/builder/googlecompute/config_test.go
index 051c3797b..dab12c9f9 100644
--- a/builder/googlecompute/config_test.go
+++ b/builder/googlecompute/config_test.go
@@ -7,6 +7,8 @@ import (
 	"runtime"
 	"strings"
 	"testing"
+
+	"github.com/hashicorp/packer/helper/communicator"
 )
 
 func TestConfigPrepare(t *testing.T) {
@@ -383,7 +385,7 @@ func TestConfigPrepareStartupScriptFile(t *testing.T) {
 	}
 }
 
-func TestConfigPrepareIAP(t *testing.T) {
+func TestConfigPrepareIAP_SSH(t *testing.T) {
 	config := map[string]interface{}{
 		"project_id":   "project",
 		"source_image": "foo",
@@ -398,25 +400,33 @@ func TestConfigPrepareIAP(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Shouldn't have errors. Err = %s", err)
 	}
-
-	if runtime.GOOS == "windows" {
-		if c.IAPExt != ".cmd" {
-			t.Fatalf("IAP tempfile extension didn't default correctly to .cmd")
-		}
-		if c.IAPHashBang != "" {
-			t.Fatalf("IAP hashbang didn't default correctly to nothing.")
-		}
-	} else {
-		if c.IAPExt != "" {
-			t.Fatalf("IAP tempfile extension should default to empty on unix mahcines")
-		}
-		if c.IAPHashBang != "/bin/sh" {
-			t.Fatalf("IAP hashbang didn't default correctly to /bin/sh.")
-		}
-	}
 	if c.Comm.SSHHost != "localhost" {
-		t.Fatalf("Didn't correctly override the ssh host.")
+		t.Fatalf("Should have set SSHHost")
 	}
+
+	testIAPScript(t, &c)
+}
+
+func TestConfigPrepareIAP_WinRM(t *testing.T) {
+	config := map[string]interface{}{
+		"project_id":     "project",
+		"source_image":   "foo",
+		"winrm_username": "packer",
+		"zone":           "us-central1-a",
+		"communicator":   "winrm",
+		"use_iap":        true,
+	}
+
+	var c Config
+	_, err := c.Prepare(config)
+	if err != nil {
+		t.Fatalf("Shouldn't have errors. Err = %s", err)
+	}
+	if c.Comm.WinRMHost != "localhost" {
+		t.Fatalf("Should have set WinRMHost")
+	}
+
+	testIAPScript(t, &c)
 }
 
 func TestConfigPrepareIAP_failures(t *testing.T) {
@@ -425,7 +435,7 @@ func TestConfigPrepareIAP_failures(t *testing.T) {
 		"source_image":   "foo",
 		"winrm_username": "packer",
 		"zone":           "us-central1-a",
-		"communicator":   "winrm",
+		"communicator":   "none",
 		"iap_hashbang":   "/bin/bash",
 		"iap_ext":        ".ps1",
 		"use_iap":        true,
@@ -434,7 +444,7 @@ func TestConfigPrepareIAP_failures(t *testing.T) {
 	var c Config
 	_, errs := c.Prepare(config)
 	if errs == nil {
-		t.Fatalf("Should have errored because we're using winrm.")
+		t.Fatalf("Should have errored because we're using none.")
 	}
 	if c.IAPHashBang != "/bin/bash" {
 		t.Fatalf("IAP hashbang defaulted even though set.")
@@ -500,6 +510,53 @@ func TestRegion(t *testing.T) {
 	}
 }
 
+func TestApplyIAPTunnel_SSH(t *testing.T) {
+	c := &communicator.Config{
+		Type: "ssh",
+		SSH: communicator.SSH{
+			SSHHost: "example",
+			SSHPort: 1234,
+		},
+	}
+
+	err := ApplyIAPTunnel(c, 8447)
+	if err != nil {
+		t.Fatalf("Shouldn't have errors")
+	}
+	if c.SSHPort != 8447 {
+		t.Fatalf("Should have set SSHPort")
+	}
+}
+
+func TestApplyIAPTunnel_WinRM(t *testing.T) {
+	c := &communicator.Config{
+		Type: "winrm",
+		WinRM: communicator.WinRM{
+			WinRMHost: "example",
+			WinRMPort: 1234,
+		},
+	}
+
+	err := ApplyIAPTunnel(c, 8447)
+	if err != nil {
+		t.Fatalf("Shouldn't have errors")
+	}
+	if c.WinRMPort != 8447 {
+		t.Fatalf("Should have set WinRMPort")
+	}
+}
+
+func TestApplyIAPTunnel_none(t *testing.T) {
+	c := &communicator.Config{
+		Type: "none",
+	}
+
+	err := ApplyIAPTunnel(c, 8447)
+	if err == nil {
+		t.Fatalf("Should have errors, none is not supported")
+	}
+}
+
 // Helper stuff below
 
 func testConfig(t *testing.T) (config map[string]interface{}, tempAccountFile string) {
@@ -576,6 +633,24 @@ func testAccountFile(t *testing.T) string {
 	return tf.Name()
 }
 
+func testIAPScript(t *testing.T, c *Config) {
+	if runtime.GOOS == "windows" {
+		if c.IAPExt != ".cmd" {
+			t.Fatalf("IAP tempfile extension didn't default correctly to .cmd")
+		}
+		if c.IAPHashBang != "" {
+			t.Fatalf("IAP hashbang didn't default correctly to nothing.")
+		}
+	} else {
+		if c.IAPExt != "" {
+			t.Fatalf("IAP tempfile extension should default to empty on unix mahcines")
+		}
+		if c.IAPHashBang != "/bin/sh" {
+			t.Fatalf("IAP hashbang didn't default correctly to /bin/sh.")
+		}
+	}
+}
+
 const testMetadataFileContent = `testMetadata`
 
 func testMetadataFile(t *testing.T) string {
diff --git a/builder/googlecompute/step_start_tunnel.go b/builder/googlecompute/step_start_tunnel.go
index 15020281a..f52839e8a 100644
--- a/builder/googlecompute/step_start_tunnel.go
+++ b/builder/googlecompute/step_start_tunnel.go
@@ -34,8 +34,6 @@ type IAPConfig struct {
 	// - You must have the gcloud sdk installed on the computer running Packer.
 	// - You must be using a Service Account with a credentials file (using the
 	//	 account_file option in the Packer template)
-	// - This is currently only implemented for the SSH communicator, not the
-	//   WinRM Communicator.
 	// - You must add the given service account to project level IAP permissions
 	//   in https://console.cloud.google.com/security/iap. To do so, click
 	//   "project" > "SSH and TCP resoures" > "All Tunnel Resources" >
@@ -52,7 +50,7 @@ type IAPConfig struct {
 	// Default: ".sh"
 	IAPExt string `mapstructure:"iap_ext" required:"false"`
 	// How long to wait, in seconds, before assuming a tunnel launch was
-	// successful. Defaults to 30 seconds.
+	// successful. Defaults to 30 seconds for SSH or 40 seconds for WinRM.
 	IAPTunnelLaunchWait int `mapstructure:"iap_tunnel_launch_wait" required:"false"`
 }
 
@@ -283,7 +281,14 @@ func (s *StepStartTunnel) Run(ctx context.Context, state multistep.StateBag) mul
 
 	// This is the port the IAP tunnel listens on, on localhost.
 	// TODO make setting LocalHostPort optional
-	s.CommConf.SSHPort = s.IAPConf.IAPLocalhostPort
+	err = ApplyIAPTunnel(s.CommConf, s.IAPConf.IAPLocalhostPort)
+	if err != nil {
+		// this should not occur as the config should validate that the communicator
+		// supports using an IAP tunnel
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
 
 	log.Printf("Creating tunnel launch script with args %#v", args)
 	// Create temp file that contains both gcloud authentication, and gcloud
diff --git a/website/pages/partials/builder/googlecompute/IAPConfig-not-required.mdx b/website/pages/partials/builder/googlecompute/IAPConfig-not-required.mdx
index 7e9f2aa21..0ce215f50 100644
--- a/website/pages/partials/builder/googlecompute/IAPConfig-not-required.mdx
+++ b/website/pages/partials/builder/googlecompute/IAPConfig-not-required.mdx
@@ -6,8 +6,6 @@
   - You must have the gcloud sdk installed on the computer running Packer.
   - You must be using a Service Account with a credentials file (using the
   	 account_file option in the Packer template)
-  - This is currently only implemented for the SSH communicator, not the
-    WinRM Communicator.
   - You must add the given service account to project level IAP permissions
     in https://console.cloud.google.com/security/iap. To do so, click
     "project" > "SSH and TCP resoures" > "All Tunnel Resources" >
@@ -24,4 +22,4 @@
   Default: ".sh"
 
 - `iap_tunnel_launch_wait` (int) - How long to wait, in seconds, before assuming a tunnel launch was
-  successful. Defaults to 30 seconds.
+  successful. Defaults to 30 seconds for SSH or 40 seconds for WinRM.