diff --git a/builder/vmware/builder.go b/builder/vmware/builder.go
index 501e942e7..80627df56 100644
--- a/builder/vmware/builder.go
+++ b/builder/vmware/builder.go
@@ -376,12 +376,12 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 	}
 
 	// Setup the state bag
-	state := make(map[string]interface{})
-	state["cache"] = cache
-	state["config"] = &b.config
-	state["driver"] = driver
-	state["hook"] = hook
-	state["ui"] = ui
+	state := new(multistep.BasicStateBag)
+	state.Put("cache", cache)
+	state.Put("config", &b.config)
+	state.Put("driver", driver)
+	state.Put("hook", hook)
+	state.Put("ui", ui)
 
 	// Run!
 	if b.config.PackerDebug {
@@ -396,16 +396,16 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 	b.runner.Run(state)
 
 	// If there was an error, return that
-	if rawErr, ok := state["error"]; ok {
+	if rawErr, ok := state.GetOk("error"); ok {
 		return nil, rawErr.(error)
 	}
 
 	// If we were interrupted or cancelled, then just exit.
-	if _, ok := state[multistep.StateCancelled]; ok {
+	if _, ok := state.GetOk(multistep.StateCancelled); ok {
 		return nil, errors.New("Build was cancelled.")
 	}
 
-	if _, ok := state[multistep.StateHalted]; ok {
+	if _, ok := state.GetOk(multistep.StateHalted); ok {
 		return nil, errors.New("Build was halted.")
 	}
 
diff --git a/builder/vmware/ssh.go b/builder/vmware/ssh.go
index 2f1232fd6..121d79709 100644
--- a/builder/vmware/ssh.go
+++ b/builder/vmware/ssh.go
@@ -4,16 +4,17 @@ import (
 	gossh "code.google.com/p/go.crypto/ssh"
 	"errors"
 	"fmt"
+	"github.com/mitchellh/multistep"
 	"github.com/mitchellh/packer/communicator/ssh"
 	"io/ioutil"
 	"log"
 	"os"
 )
 
-func sshAddress(state map[string]interface{}) (string, error) {
-	config := state["config"].(*config)
-	driver := state["driver"].(Driver)
-	vmxPath := state["vmx_path"].(string)
+func sshAddress(state multistep.StateBag) (string, error) {
+	config := state.Get("config").(*config)
+	driver := state.Get("driver").(Driver)
+	vmxPath := state.Get("vmx_path").(string)
 
 	log.Println("Lookup up IP information...")
 	f, err := os.Open(vmxPath)
@@ -58,8 +59,8 @@ func sshAddress(state map[string]interface{}) (string, error) {
 	return fmt.Sprintf("%s:%d", ipAddress, config.SSHPort), nil
 }
 
-func sshConfig(state map[string]interface{}) (*gossh.ClientConfig, error) {
-	config := state["config"].(*config)
+func sshConfig(state multistep.StateBag) (*gossh.ClientConfig, error) {
+	config := state.Get("config").(*config)
 
 	auth := []gossh.ClientAuth{
 		gossh.ClientAuthPassword(ssh.Password(config.SSHPassword)),
diff --git a/builder/vmware/step_clean_files.go b/builder/vmware/step_clean_files.go
index ba6f4b04e..f429b4464 100644
--- a/builder/vmware/step_clean_files.go
+++ b/builder/vmware/step_clean_files.go
@@ -23,9 +23,9 @@ var KeepFileExtensions = []string{".nvram", ".vmdk", ".vmsd", ".vmx", ".vmxf"}
 //   <nothing>
 type stepCleanFiles struct{}
 
-func (stepCleanFiles) Run(state map[string]interface{}) multistep.StepAction {
-	config := state["config"].(*config)
-	ui := state["ui"].(packer.Ui)
+func (stepCleanFiles) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*config)
+	ui := state.Get("ui").(packer.Ui)
 
 	ui.Say("Deleting unnecessary VMware files...")
 	visit := func(path string, info os.FileInfo, err error) error {
@@ -55,11 +55,11 @@ func (stepCleanFiles) Run(state map[string]interface{}) multistep.StepAction {
 	}
 
 	if err := filepath.Walk(config.OutputDir, visit); err != nil {
-		state["error"] = err
+		state.Put("error", err)
 		return multistep.ActionHalt
 	}
 
 	return multistep.ActionContinue
 }
 
-func (stepCleanFiles) Cleanup(map[string]interface{}) {}
+func (stepCleanFiles) Cleanup(multistep.StateBag) {}
diff --git a/builder/vmware/step_clean_vmx.go b/builder/vmware/step_clean_vmx.go
index b6519858b..21273ffa2 100644
--- a/builder/vmware/step_clean_vmx.go
+++ b/builder/vmware/step_clean_vmx.go
@@ -22,20 +22,20 @@ import (
 //   <nothing>
 type stepCleanVMX struct{}
 
-func (s stepCleanVMX) Run(state map[string]interface{}) multistep.StepAction {
-	isoPath := state["iso_path"].(string)
-	ui := state["ui"].(packer.Ui)
-	vmxPath := state["vmx_path"].(string)
+func (s stepCleanVMX) Run(state multistep.StateBag) multistep.StepAction {
+	isoPath := state.Get("iso_path").(string)
+	ui := state.Get("ui").(packer.Ui)
+	vmxPath := state.Get("vmx_path").(string)
 
 	ui.Say("Cleaning VMX prior to finishing up...")
 
 	vmxData, err := s.readVMX(vmxPath)
 	if err != nil {
-		state["error"] = fmt.Errorf("Error reading VMX: %s", err)
+		state.Put("error", fmt.Errorf("Error reading VMX: %s", err))
 		return multistep.ActionHalt
 	}
 
-	if _, ok := state["floppy_path"]; ok {
+	if _, ok := state.GetOk("floppy_path"); ok {
 		// Delete the floppy0 entries so the floppy is no longer mounted
 		ui.Message("Unmounting floppy from VMX...")
 		for k, _ := range vmxData {
@@ -67,14 +67,14 @@ func (s stepCleanVMX) Run(state map[string]interface{}) multistep.StepAction {
 
 	// Rewrite the VMX
 	if err := WriteVMX(vmxPath, vmxData); err != nil {
-		state["error"] = fmt.Errorf("Error writing VMX: %s", err)
+		state.Put("error", fmt.Errorf("Error writing VMX: %s", err))
 		return multistep.ActionHalt
 	}
 
 	return multistep.ActionContinue
 }
 
-func (stepCleanVMX) Cleanup(map[string]interface{}) {}
+func (stepCleanVMX) Cleanup(multistep.StateBag) {}
 
 func (stepCleanVMX) readVMX(vmxPath string) (map[string]string, error) {
 	vmxF, err := os.Open(vmxPath)
diff --git a/builder/vmware/step_compact_disk.go b/builder/vmware/step_compact_disk.go
index 05bbc62da..4a87b4a1a 100644
--- a/builder/vmware/step_compact_disk.go
+++ b/builder/vmware/step_compact_disk.go
@@ -20,11 +20,11 @@ import (
 //   <nothing>
 type stepCompactDisk struct{}
 
-func (stepCompactDisk) Run(state map[string]interface{}) multistep.StepAction {
-	config := state["config"].(*config)
-	driver := state["driver"].(Driver)
-	ui := state["ui"].(packer.Ui)
-	full_disk_path := state["full_disk_path"].(string)
+func (stepCompactDisk) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*config)
+	driver := state.Get("driver").(Driver)
+	ui := state.Get("ui").(packer.Ui)
+	full_disk_path := state.Get("full_disk_path").(string)
 
 	if config.SkipCompaction == true {
 		log.Println("Skipping disk compaction step...")
@@ -33,11 +33,11 @@ func (stepCompactDisk) Run(state map[string]interface{}) multistep.StepAction {
 
 	ui.Say("Compacting the disk image")
 	if err := driver.CompactDisk(full_disk_path); err != nil {
-		state["error"] = fmt.Errorf("Error compacting disk: %s", err)
+		state.Put("error", fmt.Errorf("Error compacting disk: %s", err))
 		return multistep.ActionHalt
 	}
 
 	return multistep.ActionContinue
 }
 
-func (stepCompactDisk) Cleanup(map[string]interface{}) {}
+func (stepCompactDisk) Cleanup(multistep.StateBag) {}
diff --git a/builder/vmware/step_configure_vnc.go b/builder/vmware/step_configure_vnc.go
index 341097949..bee28c8d4 100644
--- a/builder/vmware/step_configure_vnc.go
+++ b/builder/vmware/step_configure_vnc.go
@@ -22,15 +22,15 @@ import (
 //   vnc_port uint - The port that VNC is configured to listen on.
 type stepConfigureVNC struct{}
 
-func (stepConfigureVNC) Run(state map[string]interface{}) multistep.StepAction {
-	config := state["config"].(*config)
-	ui := state["ui"].(packer.Ui)
-	vmxPath := state["vmx_path"].(string)
+func (stepConfigureVNC) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*config)
+	ui := state.Get("ui").(packer.Ui)
+	vmxPath := state.Get("vmx_path").(string)
 
 	f, err := os.Open(vmxPath)
 	if err != nil {
 		err := fmt.Errorf("Error reading VMX data: %s", err)
-		state["error"] = err
+		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
@@ -38,7 +38,7 @@ func (stepConfigureVNC) Run(state map[string]interface{}) multistep.StepAction {
 	vmxBytes, err := ioutil.ReadAll(f)
 	if err != nil {
 		err := fmt.Errorf("Error reading VMX data: %s", err)
-		state["error"] = err
+		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
@@ -67,15 +67,15 @@ func (stepConfigureVNC) Run(state map[string]interface{}) multistep.StepAction {
 
 	if err := WriteVMX(vmxPath, vmxData); err != nil {
 		err := fmt.Errorf("Error writing VMX data: %s", err)
-		state["error"] = err
+		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
 
-	state["vnc_port"] = vncPort
+	state.Put("vnc_port", vncPort)
 
 	return multistep.ActionContinue
 }
 
-func (stepConfigureVNC) Cleanup(map[string]interface{}) {
+func (stepConfigureVNC) Cleanup(multistep.StateBag) {
 }
diff --git a/builder/vmware/step_create_disk.go b/builder/vmware/step_create_disk.go
index 00bb0e2e2..3b526812e 100644
--- a/builder/vmware/step_create_disk.go
+++ b/builder/vmware/step_create_disk.go
@@ -18,23 +18,23 @@ import (
 //   full_disk_path (string) - The full path to the created disk.
 type stepCreateDisk struct{}
 
-func (stepCreateDisk) Run(state map[string]interface{}) multistep.StepAction {
-	config := state["config"].(*config)
-	driver := state["driver"].(Driver)
-	ui := state["ui"].(packer.Ui)
+func (stepCreateDisk) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*config)
+	driver := state.Get("driver").(Driver)
+	ui := state.Get("ui").(packer.Ui)
 
 	ui.Say("Creating virtual machine disk")
 	full_disk_path := filepath.Join(config.OutputDir, config.DiskName+".vmdk")
 	if err := driver.CreateDisk(full_disk_path, fmt.Sprintf("%dM", config.DiskSize), config.DiskTypeId); err != nil {
 		err := fmt.Errorf("Error creating disk: %s", err)
-		state["error"] = err
+		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
 
-	state["full_disk_path"] = full_disk_path
+	state.Put("full_disk_path", full_disk_path)
 
 	return multistep.ActionContinue
 }
 
-func (stepCreateDisk) Cleanup(map[string]interface{}) {}
+func (stepCreateDisk) Cleanup(multistep.StateBag) {}
diff --git a/builder/vmware/step_create_vmx.go b/builder/vmware/step_create_vmx.go
index 91a2b474b..311b7a9ca 100644
--- a/builder/vmware/step_create_vmx.go
+++ b/builder/vmware/step_create_vmx.go
@@ -28,10 +28,10 @@ type vmxTemplateData struct {
 //   vmx_path string - The path to the VMX file.
 type stepCreateVMX struct{}
 
-func (stepCreateVMX) Run(state map[string]interface{}) multistep.StepAction {
-	config := state["config"].(*config)
-	isoPath := state["iso_path"].(string)
-	ui := state["ui"].(packer.Ui)
+func (stepCreateVMX) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*config)
+	isoPath := state.Get("iso_path").(string)
+	ui := state.Get("ui").(packer.Ui)
 
 	ui.Say("Building and writing VMX file")
 
@@ -47,7 +47,7 @@ func (stepCreateVMX) Run(state map[string]interface{}) multistep.StepAction {
 		f, err := os.Open(config.VMXTemplatePath)
 		if err != nil {
 			err := fmt.Errorf("Error reading VMX template: %s", err)
-			state["error"] = err
+			state.Put("error", err)
 			ui.Error(err.Error())
 			return multistep.ActionHalt
 		}
@@ -56,7 +56,7 @@ func (stepCreateVMX) Run(state map[string]interface{}) multistep.StepAction {
 		rawBytes, err := ioutil.ReadAll(f)
 		if err != nil {
 			err := fmt.Errorf("Error reading VMX template: %s", err)
-			state["error"] = err
+			state.Put("error", err)
 			ui.Error(err.Error())
 			return multistep.ActionHalt
 		}
@@ -67,7 +67,7 @@ func (stepCreateVMX) Run(state map[string]interface{}) multistep.StepAction {
 	vmxContents, err := config.tpl.Process(vmxTemplate, tplData)
 	if err != nil {
 		err := fmt.Errorf("Error procesing VMX template: %s", err)
-		state["error"] = err
+		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
@@ -81,7 +81,7 @@ func (stepCreateVMX) Run(state map[string]interface{}) multistep.StepAction {
 		}
 	}
 
-	if floppyPathRaw, ok := state["floppy_path"]; ok {
+	if floppyPathRaw, ok := state.GetOk("floppy_path"); ok {
 		log.Println("Floppy path present, setting in VMX")
 		vmxData["floppy0.present"] = "TRUE"
 		vmxData["floppy0.fileType"] = "file"
@@ -91,17 +91,17 @@ func (stepCreateVMX) Run(state map[string]interface{}) multistep.StepAction {
 	vmxPath := filepath.Join(config.OutputDir, config.VMName+".vmx")
 	if err := WriteVMX(vmxPath, vmxData); err != nil {
 		err := fmt.Errorf("Error creating VMX file: %s", err)
-		state["error"] = err
+		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
 
-	state["vmx_path"] = vmxPath
+	state.Put("vmx_path", vmxPath)
 
 	return multistep.ActionContinue
 }
 
-func (stepCreateVMX) Cleanup(map[string]interface{}) {
+func (stepCreateVMX) Cleanup(multistep.StateBag) {
 }
 
 // This is the default VMX template used if no other template is given.
diff --git a/builder/vmware/step_http_server.go b/builder/vmware/step_http_server.go
index af4a35beb..084816f63 100644
--- a/builder/vmware/step_http_server.go
+++ b/builder/vmware/step_http_server.go
@@ -23,13 +23,13 @@ type stepHTTPServer struct {
 	l net.Listener
 }
 
-func (s *stepHTTPServer) Run(state map[string]interface{}) multistep.StepAction {
-	config := state["config"].(*config)
-	ui := state["ui"].(packer.Ui)
+func (s *stepHTTPServer) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*config)
+	ui := state.Get("ui").(packer.Ui)
 
 	var httpPort uint = 0
 	if config.HTTPDir == "" {
-		state["http_port"] = httpPort
+		state.Put("http_port", httpPort)
 		return multistep.ActionContinue
 	}
 
@@ -62,12 +62,12 @@ func (s *stepHTTPServer) Run(state map[string]interface{}) multistep.StepAction
 	go server.Serve(s.l)
 
 	// Save the address into the state so it can be accessed in the future
-	state["http_port"] = httpPort
+	state.Put("http_port", httpPort)
 
 	return multistep.ActionContinue
 }
 
-func (s *stepHTTPServer) Cleanup(map[string]interface{}) {
+func (s *stepHTTPServer) Cleanup(multistep.StateBag) {
 	if s.l != nil {
 		// Close the listener so that the HTTP server stops
 		s.l.Close()
diff --git a/builder/vmware/step_prepare_output_dir.go b/builder/vmware/step_prepare_output_dir.go
index 738bedca3..bb5149cad 100644
--- a/builder/vmware/step_prepare_output_dir.go
+++ b/builder/vmware/step_prepare_output_dir.go
@@ -10,9 +10,9 @@ import (
 
 type stepPrepareOutputDir struct{}
 
-func (stepPrepareOutputDir) Run(state map[string]interface{}) multistep.StepAction {
-	config := state["config"].(*config)
-	ui := state["ui"].(packer.Ui)
+func (stepPrepareOutputDir) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*config)
+	ui := state.Get("ui").(packer.Ui)
 
 	if _, err := os.Stat(config.OutputDir); err == nil && config.PackerForce {
 		ui.Say("Deleting previous output directory...")
@@ -20,20 +20,20 @@ func (stepPrepareOutputDir) Run(state map[string]interface{}) multistep.StepActi
 	}
 
 	if err := os.MkdirAll(config.OutputDir, 0755); err != nil {
-		state["error"] = err
+		state.Put("error", err)
 		return multistep.ActionHalt
 	}
 
 	return multistep.ActionContinue
 }
 
-func (stepPrepareOutputDir) Cleanup(state map[string]interface{}) {
-	_, cancelled := state[multistep.StateCancelled]
-	_, halted := state[multistep.StateHalted]
+func (stepPrepareOutputDir) Cleanup(state multistep.StateBag) {
+	_, cancelled := state.GetOk(multistep.StateCancelled)
+	_, halted := state.GetOk(multistep.StateHalted)
 
 	if cancelled || halted {
-		config := state["config"].(*config)
-		ui := state["ui"].(packer.Ui)
+		config := state.Get("config").(*config)
+		ui := state.Get("ui").(packer.Ui)
 
 		ui.Say("Deleting output directory...")
 		for i := 0; i < 5; i++ {
diff --git a/builder/vmware/step_prepare_tools.go b/builder/vmware/step_prepare_tools.go
index 0df461321..e26bcf8ed 100644
--- a/builder/vmware/step_prepare_tools.go
+++ b/builder/vmware/step_prepare_tools.go
@@ -8,9 +8,9 @@ import (
 
 type stepPrepareTools struct{}
 
-func (*stepPrepareTools) Run(state map[string]interface{}) multistep.StepAction {
-	config := state["config"].(*config)
-	driver := state["driver"].(Driver)
+func (*stepPrepareTools) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*config)
+	driver := state.Get("driver").(Driver)
 
 	if config.ToolsUploadFlavor == "" {
 		return multistep.ActionContinue
@@ -18,16 +18,16 @@ func (*stepPrepareTools) Run(state map[string]interface{}) multistep.StepAction
 
 	path := driver.ToolsIsoPath(config.ToolsUploadFlavor)
 	if _, err := os.Stat(path); err != nil {
-		state["error"] = fmt.Errorf(
+		state.Put("error", fmt.Errorf(
 			"Couldn't find VMware tools for '%s'! VMware often downloads these\n"+
 				"tools on-demand. However, to do this, you need to create a fake VM\n"+
 				"of the proper type then click the 'install tools' option in the\n"+
-				"VMware GUI.", config.ToolsUploadFlavor)
+				"VMware GUI.", config.ToolsUploadFlavor))
 		return multistep.ActionHalt
 	}
 
-	state["tools_upload_source"] = path
+	state.Put("tools_upload_source", path)
 	return multistep.ActionContinue
 }
 
-func (*stepPrepareTools) Cleanup(map[string]interface{}) {}
+func (*stepPrepareTools) Cleanup(multistep.StateBag) {}
diff --git a/builder/vmware/step_run.go b/builder/vmware/step_run.go
index 75ce071f7..2fe56eec7 100644
--- a/builder/vmware/step_run.go
+++ b/builder/vmware/step_run.go
@@ -22,12 +22,12 @@ type stepRun struct {
 	vmxPath  string
 }
 
-func (s *stepRun) Run(state map[string]interface{}) multistep.StepAction {
-	config := state["config"].(*config)
-	driver := state["driver"].(Driver)
-	ui := state["ui"].(packer.Ui)
-	vmxPath := state["vmx_path"].(string)
-	vncPort := state["vnc_port"].(uint)
+func (s *stepRun) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*config)
+	driver := state.Get("driver").(Driver)
+	ui := state.Get("ui").(packer.Ui)
+	vmxPath := state.Get("vmx_path").(string)
+	vncPort := state.Get("vnc_port").(uint)
 
 	// Set the VMX path so that we know we started the machine
 	s.bootTime = time.Now()
@@ -43,7 +43,7 @@ func (s *stepRun) Run(state map[string]interface{}) multistep.StepAction {
 
 	if err := driver.Start(vmxPath, config.Headless); err != nil {
 		err := fmt.Errorf("Error starting VM: %s", err)
-		state["error"] = err
+		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
@@ -57,9 +57,9 @@ func (s *stepRun) Run(state map[string]interface{}) multistep.StepAction {
 	return multistep.ActionContinue
 }
 
-func (s *stepRun) Cleanup(state map[string]interface{}) {
-	driver := state["driver"].(Driver)
-	ui := state["ui"].(packer.Ui)
+func (s *stepRun) Cleanup(state multistep.StateBag) {
+	driver := state.Get("driver").(Driver)
+	ui := state.Get("ui").(packer.Ui)
 
 	// If we started the machine... stop it.
 	if s.vmxPath != "" {
diff --git a/builder/vmware/step_shutdown.go b/builder/vmware/step_shutdown.go
index 4355a047f..dae402763 100644
--- a/builder/vmware/step_shutdown.go
+++ b/builder/vmware/step_shutdown.go
@@ -27,12 +27,12 @@ import (
 //   <nothing>
 type stepShutdown struct{}
 
-func (s *stepShutdown) Run(state map[string]interface{}) multistep.StepAction {
-	comm := state["communicator"].(packer.Communicator)
-	config := state["config"].(*config)
-	driver := state["driver"].(Driver)
-	ui := state["ui"].(packer.Ui)
-	vmxPath := state["vmx_path"].(string)
+func (s *stepShutdown) Run(state multistep.StateBag) multistep.StepAction {
+	comm := state.Get("communicator").(packer.Communicator)
+	config := state.Get("config").(*config)
+	driver := state.Get("driver").(Driver)
+	ui := state.Get("ui").(packer.Ui)
+	vmxPath := state.Get("vmx_path").(string)
 
 	if config.ShutdownCommand != "" {
 		ui.Say("Gracefully halting virtual machine...")
@@ -46,7 +46,7 @@ func (s *stepShutdown) Run(state map[string]interface{}) multistep.StepAction {
 		}
 		if err := comm.Start(cmd); err != nil {
 			err := fmt.Errorf("Failed to send shutdown command: %s", err)
-			state["error"] = err
+			state.Put("error", err)
 			ui.Error(err.Error())
 			return multistep.ActionHalt
 		}
@@ -56,9 +56,9 @@ func (s *stepShutdown) Run(state map[string]interface{}) multistep.StepAction {
 
 		// If the command failed to run, notify the user in some way.
 		if cmd.ExitStatus != 0 {
-			state["error"] = fmt.Errorf(
+			state.Put("error", fmt.Errorf(
 				"Shutdown command has non-zero exit status.\n\nStdout: %s\n\nStderr: %s",
-				stdout.String(), stderr.String())
+				stdout.String(), stderr.String()))
 			return multistep.ActionHalt
 		}
 
@@ -77,7 +77,7 @@ func (s *stepShutdown) Run(state map[string]interface{}) multistep.StepAction {
 			select {
 			case <-shutdownTimer:
 				err := errors.New("Timeout while waiting for machine to shut down.")
-				state["error"] = err
+				state.Put("error", err)
 				ui.Error(err.Error())
 				return multistep.ActionHalt
 			default:
@@ -87,7 +87,7 @@ func (s *stepShutdown) Run(state map[string]interface{}) multistep.StepAction {
 	} else {
 		if err := driver.Stop(vmxPath); err != nil {
 			err := fmt.Errorf("Error stopping VM: %s", err)
-			state["error"] = err
+			state.Put("error", err)
 			ui.Error(err.Error())
 			return multistep.ActionHalt
 		}
@@ -132,4 +132,4 @@ LockWaitLoop:
 	return multistep.ActionContinue
 }
 
-func (s *stepShutdown) Cleanup(state map[string]interface{}) {}
+func (s *stepShutdown) Cleanup(state multistep.StateBag) {}
diff --git a/builder/vmware/step_type_boot_command.go b/builder/vmware/step_type_boot_command.go
index 2bc831913..804328613 100644
--- a/builder/vmware/step_type_boot_command.go
+++ b/builder/vmware/step_type_boot_command.go
@@ -34,18 +34,18 @@ type bootCommandTemplateData struct {
 //   <nothing>
 type stepTypeBootCommand struct{}
 
-func (s *stepTypeBootCommand) Run(state map[string]interface{}) multistep.StepAction {
-	config := state["config"].(*config)
-	httpPort := state["http_port"].(uint)
-	ui := state["ui"].(packer.Ui)
-	vncPort := state["vnc_port"].(uint)
+func (s *stepTypeBootCommand) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*config)
+	httpPort := state.Get("http_port").(uint)
+	ui := state.Get("ui").(packer.Ui)
+	vncPort := state.Get("vnc_port").(uint)
 
 	// Connect to VNC
 	ui.Say("Connecting to VM via VNC")
 	nc, err := net.Dial("tcp", fmt.Sprintf("127.0.0.1:%d", vncPort))
 	if err != nil {
 		err := fmt.Errorf("Error connecting to VNC: %s", err)
-		state["error"] = err
+		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
@@ -54,7 +54,7 @@ func (s *stepTypeBootCommand) Run(state map[string]interface{}) multistep.StepAc
 	c, err := vnc.Client(nc, &vnc.ClientConfig{Exclusive: true})
 	if err != nil {
 		err := fmt.Errorf("Error handshaking with VNC: %s", err)
-		state["error"] = err
+		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
@@ -73,7 +73,7 @@ func (s *stepTypeBootCommand) Run(state map[string]interface{}) multistep.StepAc
 	hostIp, err := ipFinder.HostIP()
 	if err != nil {
 		err := fmt.Errorf("Error detecting host IP: %s", err)
-		state["error"] = err
+		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
@@ -91,14 +91,14 @@ func (s *stepTypeBootCommand) Run(state map[string]interface{}) multistep.StepAc
 		command, err := config.tpl.Process(command, tplData)
 		if err != nil {
 			err := fmt.Errorf("Error preparing boot command: %s", err)
-			state["error"] = err
+			state.Put("error", err)
 			ui.Error(err.Error())
 			return multistep.ActionHalt
 		}
 
 		// Check for interrupts between typing things so we can cancel
 		// since this isn't the fastest thing.
-		if _, ok := state[multistep.StateCancelled]; ok {
+		if _, ok := state.GetOk(multistep.StateCancelled); ok {
 			return multistep.ActionHalt
 		}
 
@@ -108,7 +108,7 @@ func (s *stepTypeBootCommand) Run(state map[string]interface{}) multistep.StepAc
 	return multistep.ActionContinue
 }
 
-func (*stepTypeBootCommand) Cleanup(map[string]interface{}) {}
+func (*stepTypeBootCommand) Cleanup(multistep.StateBag) {}
 
 func vncSendString(c *vnc.ClientConn, original string) {
 	special := make(map[string]uint32)
diff --git a/builder/vmware/step_upload_tools.go b/builder/vmware/step_upload_tools.go
index 9bbc5572a..630faef8d 100644
--- a/builder/vmware/step_upload_tools.go
+++ b/builder/vmware/step_upload_tools.go
@@ -13,20 +13,20 @@ type toolsUploadPathTemplate struct {
 
 type stepUploadTools struct{}
 
-func (*stepUploadTools) Run(state map[string]interface{}) multistep.StepAction {
-	config := state["config"].(*config)
+func (*stepUploadTools) Run(state multistep.StateBag) multistep.StepAction {
+	config := state.Get("config").(*config)
 	if config.ToolsUploadFlavor == "" {
 		return multistep.ActionContinue
 	}
 
-	comm := state["communicator"].(packer.Communicator)
-	tools_source := state["tools_upload_source"].(string)
-	ui := state["ui"].(packer.Ui)
+	comm := state.Get("communicator").(packer.Communicator)
+	tools_source := state.Get("tools_upload_source").(string)
+	ui := state.Get("ui").(packer.Ui)
 
 	ui.Say(fmt.Sprintf("Uploading the '%s' VMware Tools", config.ToolsUploadFlavor))
 	f, err := os.Open(tools_source)
 	if err != nil {
-		state["error"] = fmt.Errorf("Error opening VMware Tools ISO: %s", err)
+		state.Put("error", fmt.Errorf("Error opening VMware Tools ISO: %s", err))
 		return multistep.ActionHalt
 	}
 	defer f.Close()
@@ -35,17 +35,17 @@ func (*stepUploadTools) Run(state map[string]interface{}) multistep.StepAction {
 	config.ToolsUploadPath, err = config.tpl.Process(config.ToolsUploadPath, tplData)
 	if err != nil {
 		err := fmt.Errorf("Error preparing upload path: %s", err)
-		state["error"] = err
+		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
 
 	if err := comm.Upload(config.ToolsUploadPath, f); err != nil {
-		state["error"] = fmt.Errorf("Error uploading VMware Tools: %s", err)
+		state.Put("error", fmt.Errorf("Error uploading VMware Tools: %s", err))
 		return multistep.ActionHalt
 	}
 
 	return multistep.ActionContinue
 }
 
-func (*stepUploadTools) Cleanup(map[string]interface{}) {}
+func (*stepUploadTools) Cleanup(multistep.StateBag) {}