diff --git a/internal/cli/banger.go b/internal/cli/banger.go
index b7f3361..9de83e5 100644
--- a/internal/cli/banger.go
+++ b/internal/cli/banger.go
@@ -300,10 +300,10 @@ func newVMCreateCommand() *cobra.Command {
 	var (
 		name              string
 		imageName         string
-		vcpu              int
-		memory            int
-		systemOverlaySize string
-		workDiskSize      string
+		vcpu              = model.DefaultVCPUCount
+		memory            = model.DefaultMemoryMiB
+		systemOverlaySize = model.FormatSizeBytes(model.DefaultSystemOverlaySize)
+		workDiskSize      = model.FormatSizeBytes(model.DefaultWorkDiskSize)
 		natEnabled        bool
 		noStart           bool
 	)
@@ -332,10 +332,10 @@ func newVMCreateCommand() *cobra.Command {
 	}
 	cmd.Flags().StringVar(&name, "name", "", "vm name")
 	cmd.Flags().StringVar(&imageName, "image", "", "image name or id")
-	cmd.Flags().IntVar(&vcpu, "vcpu", 0, "vcpu count")
-	cmd.Flags().IntVar(&memory, "memory", 0, "memory in MiB")
-	cmd.Flags().StringVar(&systemOverlaySize, "system-overlay-size", "", "system overlay size")
-	cmd.Flags().StringVar(&workDiskSize, "disk-size", "", "work disk size")
+	cmd.Flags().IntVar(&vcpu, "vcpu", model.DefaultVCPUCount, "vcpu count")
+	cmd.Flags().IntVar(&memory, "memory", model.DefaultMemoryMiB, "memory in MiB")
+	cmd.Flags().StringVar(&systemOverlaySize, "system-overlay-size", model.FormatSizeBytes(model.DefaultSystemOverlaySize), "system overlay size")
+	cmd.Flags().StringVar(&workDiskSize, "disk-size", model.FormatSizeBytes(model.DefaultWorkDiskSize), "work disk size")
 	cmd.Flags().BoolVar(&natEnabled, "nat", false, "enable NAT")
 	cmd.Flags().BoolVar(&noStart, "no-start", false, "create without starting")
 	return cmd
@@ -1019,12 +1019,10 @@ func vmSetParamsFromFlags(idOrName string, vcpu, memory int, diskSize string, na
 
 func vmCreateParamsFromFlags(cmd *cobra.Command, name, imageName string, vcpu, memory int, systemOverlaySize, workDiskSize string, natEnabled, noStart bool) (api.VMCreateParams, error) {
 	params := api.VMCreateParams{
-		Name:              name,
-		ImageName:         imageName,
-		SystemOverlaySize: systemOverlaySize,
-		WorkDiskSize:      workDiskSize,
-		NATEnabled:        natEnabled,
-		NoStart:           noStart,
+		Name:       name,
+		ImageName:  imageName,
+		NATEnabled: natEnabled,
+		NoStart:    noStart,
 	}
 	if cmd.Flags().Changed("vcpu") {
 		if err := validatePositiveSetting("vcpu", vcpu); err != nil {
@@ -1038,6 +1036,12 @@ func vmCreateParamsFromFlags(cmd *cobra.Command, name, imageName string, vcpu, m
 		}
 		params.MemoryMiB = &memory
 	}
+	if cmd.Flags().Changed("system-overlay-size") {
+		params.SystemOverlaySize = systemOverlaySize
+	}
+	if cmd.Flags().Changed("disk-size") {
+		params.WorkDiskSize = workDiskSize
+	}
 	return params, nil
 }
 
diff --git a/internal/cli/cli_test.go b/internal/cli/cli_test.go
index 54af725..da0869d 100644
--- a/internal/cli/cli_test.go
+++ b/internal/cli/cli_test.go
@@ -128,6 +128,31 @@ func TestVMCreateFlagsExist(t *testing.T) {
 	}
 }
 
+func TestVMCreateFlagsShowStaticDefaults(t *testing.T) {
+	root := NewBangerCommand()
+	vm, _, err := root.Find([]string{"vm"})
+	if err != nil {
+		t.Fatalf("find vm: %v", err)
+	}
+	create, _, err := vm.Find([]string{"create"})
+	if err != nil {
+		t.Fatalf("find create: %v", err)
+	}
+
+	if got := create.Flags().Lookup("vcpu").DefValue; got != fmt.Sprintf("%d", model.DefaultVCPUCount) {
+		t.Fatalf("vcpu default = %q, want %d", got, model.DefaultVCPUCount)
+	}
+	if got := create.Flags().Lookup("memory").DefValue; got != fmt.Sprintf("%d", model.DefaultMemoryMiB) {
+		t.Fatalf("memory default = %q, want %d", got, model.DefaultMemoryMiB)
+	}
+	if got := create.Flags().Lookup("system-overlay-size").DefValue; got != model.FormatSizeBytes(model.DefaultSystemOverlaySize) {
+		t.Fatalf("system-overlay-size default = %q, want %q", got, model.FormatSizeBytes(model.DefaultSystemOverlaySize))
+	}
+	if got := create.Flags().Lookup("disk-size").DefValue; got != model.FormatSizeBytes(model.DefaultWorkDiskSize) {
+		t.Fatalf("disk-size default = %q, want %q", got, model.FormatSizeBytes(model.DefaultWorkDiskSize))
+	}
+}
+
 func TestImageRegisterFlagsExist(t *testing.T) {
 	root := NewBangerCommand()
 	image, _, err := root.Find([]string{"image"})
@@ -199,7 +224,7 @@ func TestVMSetParamsFromFlags(t *testing.T) {
 	}
 }
 
-func TestVMCreateParamsFromFlagsUsesNilForOmittedCPUAndMemory(t *testing.T) {
+func TestVMCreateParamsFromFlagsOmitsStaticDefaultsWhenFlagsAreUnchanged(t *testing.T) {
 	cmd := NewBangerCommand()
 	vm, _, err := cmd.Find([]string{"vm"})
 	if err != nil {
@@ -210,12 +235,48 @@ func TestVMCreateParamsFromFlagsUsesNilForOmittedCPUAndMemory(t *testing.T) {
 		t.Fatalf("find create: %v", err)
 	}
 
-	params, err := vmCreateParamsFromFlags(create, "devbox", "default", 0, 0, "8G", "16G", false, false)
+	params, err := vmCreateParamsFromFlags(
+		create,
+		"devbox",
+		"default",
+		model.DefaultVCPUCount,
+		model.DefaultMemoryMiB,
+		model.FormatSizeBytes(model.DefaultSystemOverlaySize),
+		model.FormatSizeBytes(model.DefaultWorkDiskSize),
+		false,
+		false,
+	)
 	if err != nil {
 		t.Fatalf("vmCreateParamsFromFlags: %v", err)
 	}
-	if params.VCPUCount != nil || params.MemoryMiB != nil {
-		t.Fatalf("expected omitted cpu/memory to stay nil: %+v", params)
+	if params.VCPUCount != nil || params.MemoryMiB != nil || params.SystemOverlaySize != "" || params.WorkDiskSize != "" {
+		t.Fatalf("expected unchanged defaults to stay omitted: %+v", params)
+	}
+}
+
+func TestVMCreateParamsFromFlagsIncludesChangedDiskFlags(t *testing.T) {
+	cmd := NewBangerCommand()
+	vm, _, err := cmd.Find([]string{"vm"})
+	if err != nil {
+		t.Fatalf("find vm: %v", err)
+	}
+	create, _, err := vm.Find([]string{"create"})
+	if err != nil {
+		t.Fatalf("find create: %v", err)
+	}
+	if err := create.Flags().Set("system-overlay-size", "16G"); err != nil {
+		t.Fatalf("set system-overlay-size flag: %v", err)
+	}
+	if err := create.Flags().Set("disk-size", "32G"); err != nil {
+		t.Fatalf("set disk-size flag: %v", err)
+	}
+
+	params, err := vmCreateParamsFromFlags(create, "devbox", "default", model.DefaultVCPUCount, model.DefaultMemoryMiB, "16G", "32G", false, false)
+	if err != nil {
+		t.Fatalf("vmCreateParamsFromFlags: %v", err)
+	}
+	if params.SystemOverlaySize != "16G" || params.WorkDiskSize != "32G" {
+		t.Fatalf("expected changed disk flags to be included: %+v", params)
 	}
 }