diff --git a/cmd/ignite-spawn/ignite-spawn.go b/cmd/ignite-spawn/ignite-spawn.go
index f85e7ccd1..14424f5c1 100644
--- a/cmd/ignite-spawn/ignite-spawn.go
+++ b/cmd/ignite-spawn/ignite-spawn.go
@@ -18,12 +18,12 @@ func main() {
 
 // Run runs the main cobra command of this application
 func Run() error {
-	if len(os.Args) != 1 {
+	if len(os.Args) != 2 {
 		fmt.Printf("Usage: ignite-spawn [VM ID]")
 		os.Exit(0)
 	}
 
-	vmID := os.Args[0]
+	vmID := os.Args[1]
 	opts, err := NewOptions(loader.NewResLoader(), vmID)
 	if err != nil {
 		return err
diff --git a/cmd/ignite/run/start.go b/cmd/ignite/run/start.go
index 3038fe935..95828b48b 100644
--- a/cmd/ignite/run/start.go
+++ b/cmd/ignite/run/start.go
@@ -117,7 +117,12 @@ func Start(so *startOptions) error {
 		return err
 	}
 
-	dockerArgs = append(dockerArgs, fmt.Sprintf("weaveworks/ignite:%s", version.GetFirecracker()))
+	// Use the :dev image tag for non-release builds
+	imageTag := version.GetIgnite().GitVersion
+	if version.GetIgnite().GitTreeState == "dirty" {
+		imageTag = "dev"
+	}
+	dockerArgs = append(dockerArgs, fmt.Sprintf("weaveworks/ignite:%s", imageTag))
 	dockerArgs = append(dockerArgs, so.vm.ID.String())
 
 	// Create the VM container in docker