diff --git a/builder/parallels/pvm/builder.go b/builder/parallels/pvm/builder.go
index 037641619..a0c7ca9cd 100644
--- a/builder/parallels/pvm/builder.go
+++ b/builder/parallels/pvm/builder.go
@@ -68,7 +68,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		new(parallelscommon.StepAttachFloppy),
 		&parallelscommon.StepPrlctl{
 			Commands: b.config.Prlctl,
-			Tpl:      b.config.tpl,
+			Ctx:      b.config.ctx,
 		},
 		&parallelscommon.StepRun{
 			BootWait: b.config.BootWait,
@@ -78,7 +78,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 			BootCommand:    b.config.BootCommand,
 			HostInterfaces: []string{},
 			VMName:         b.config.VMName,
-			Tpl:            b.config.tpl,
+			Ctx:            b.config.ctx,
 		},
 		&common.StepConnectSSH{
 			SSHAddress:     parallelscommon.SSHAddress,
@@ -92,7 +92,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 			ParallelsToolsFlavor:    b.config.ParallelsToolsFlavor,
 			ParallelsToolsGuestPath: b.config.ParallelsToolsGuestPath,
 			ParallelsToolsMode:      b.config.ParallelsToolsMode,
-			Tpl:                     b.config.tpl,
+			Ctx:                     b.config.ctx,
 		},
 		new(common.StepProvision),
 		&parallelscommon.StepShutdown{
diff --git a/builder/parallels/pvm/config.go b/builder/parallels/pvm/config.go
index 83e643111..c3fab4446 100644
--- a/builder/parallels/pvm/config.go
+++ b/builder/parallels/pvm/config.go
@@ -6,7 +6,9 @@ import (
 
 	parallelscommon "github.com/mitchellh/packer/builder/parallels/common"
 	"github.com/mitchellh/packer/common"
+	"github.com/mitchellh/packer/helper/config"
 	"github.com/mitchellh/packer/packer"
+	"github.com/mitchellh/packer/template/interpolate"
 )
 
 // Config is the configuration structure for the builder.
@@ -26,57 +28,39 @@ type Config struct {
 	VMName      string   `mapstructure:"vm_name"`
 	ReassignMac bool     `mapstructure:"reassign_mac"`
 
-	tpl *packer.ConfigTemplate
+	ctx interpolate.Context
 }
 
 func NewConfig(raws ...interface{}) (*Config, []string, error) {
 	c := new(Config)
-	md, err := common.DecodeConfig(c, raws...)
+	err := config.Decode(&c, &config.DecodeOpts{
+		Interpolate: true,
+		InterpolateFilter: &interpolate.RenderFilter{
+			Exclude: []string{
+				"boot_command",
+				"prlctl",
+				"parallel_tools_guest_path",
+			},
+		},
+	}, raws...)
 	if err != nil {
 		return nil, nil, err
 	}
 
-	c.tpl, err = packer.NewConfigTemplate()
-	if err != nil {
-		return nil, nil, err
-	}
-	c.tpl.UserVars = c.PackerUserVars
-
 	if c.VMName == "" {
 		c.VMName = fmt.Sprintf("packer-%s-{{timestamp}}", c.PackerBuildName)
 	}
 
 	// Prepare the errors
-	errs := common.CheckUnusedConfig(md)
-	errs = packer.MultiErrorAppend(errs, c.FloppyConfig.Prepare(c.tpl)...)
-	errs = packer.MultiErrorAppend(errs, c.OutputConfig.Prepare(c.tpl, &c.PackerConfig)...)
-	errs = packer.MultiErrorAppend(errs, c.PrlctlConfig.Prepare(c.tpl)...)
-	errs = packer.MultiErrorAppend(errs, c.PrlctlVersionConfig.Prepare(c.tpl)...)
-	errs = packer.MultiErrorAppend(errs, c.RunConfig.Prepare(c.tpl)...)
-	errs = packer.MultiErrorAppend(errs, c.ShutdownConfig.Prepare(c.tpl)...)
-	errs = packer.MultiErrorAppend(errs, c.SSHConfig.Prepare(c.tpl)...)
-	errs = packer.MultiErrorAppend(errs, c.ToolsConfig.Prepare(c.tpl)...)
-
-	templates := map[string]*string{
-		"source_path": &c.SourcePath,
-		"vm_name":     &c.VMName,
-	}
-
-	for n, ptr := range templates {
-		var err error
-		*ptr, err = c.tpl.Process(*ptr, nil)
-		if err != nil {
-			errs = packer.MultiErrorAppend(
-				errs, fmt.Errorf("Error processing %s: %s", n, err))
-		}
-	}
-
-	for i, command := range c.BootCommand {
-		if err := c.tpl.Validate(command); err != nil {
-			errs = packer.MultiErrorAppend(errs,
-				fmt.Errorf("Error processing boot_command[%d]: %s", i, err))
-		}
-	}
+	var errs *packer.MultiError
+	errs = packer.MultiErrorAppend(errs, c.FloppyConfig.Prepare(&c.ctx)...)
+	errs = packer.MultiErrorAppend(errs, c.OutputConfig.Prepare(&c.ctx, &c.PackerConfig)...)
+	errs = packer.MultiErrorAppend(errs, c.PrlctlConfig.Prepare(&c.ctx)...)
+	errs = packer.MultiErrorAppend(errs, c.PrlctlVersionConfig.Prepare(&c.ctx)...)
+	errs = packer.MultiErrorAppend(errs, c.RunConfig.Prepare(&c.ctx)...)
+	errs = packer.MultiErrorAppend(errs, c.ShutdownConfig.Prepare(&c.ctx)...)
+	errs = packer.MultiErrorAppend(errs, c.SSHConfig.Prepare(&c.ctx)...)
+	errs = packer.MultiErrorAppend(errs, c.ToolsConfig.Prepare(&c.ctx)...)
 
 	if c.SourcePath == "" {
 		errs = packer.MultiErrorAppend(errs, fmt.Errorf("source_path is required"))