diff --git a/builder/hyperv/iso/builder.hcl2spec.go b/builder/hyperv/iso/builder.hcl2spec.go
index d06b4b3af..5753a3f41 100644
--- a/builder/hyperv/iso/builder.hcl2spec.go
+++ b/builder/hyperv/iso/builder.hcl2spec.go
@@ -97,6 +97,7 @@ type FlatConfig struct {
 	SkipCompaction                 *bool             `mapstructure:"skip_compaction" required:"false" cty:"skip_compaction"`
 	SkipExport                     *bool             `mapstructure:"skip_export" required:"false" cty:"skip_export"`
 	Headless                       *bool             `mapstructure:"headless" required:"false" cty:"headless"`
+	LegacyGen1BootOrder            *bool             `mapstructure:"legacy_gen1_boot_order" required:"false" cty:"legacy_gen1_boot_order"`
 	ShutdownCommand                *string           `mapstructure:"shutdown_command" required:"false" cty:"shutdown_command"`
 	ShutdownTimeout                *string           `mapstructure:"shutdown_timeout" required:"false" cty:"shutdown_timeout"`
 	DiskSize                       *uint             `mapstructure:"disk_size" required:"false" cty:"disk_size"`
@@ -205,6 +206,7 @@ func (*FlatConfig) HCL2Spec() map[string]hcldec.Spec {
 		"skip_compaction":                  &hcldec.AttrSpec{Name: "skip_compaction", Type: cty.Bool, Required: false},
 		"skip_export":                      &hcldec.AttrSpec{Name: "skip_export", Type: cty.Bool, Required: false},
 		"headless":                         &hcldec.AttrSpec{Name: "headless", Type: cty.Bool, Required: false},
+		"legacy_gen1_boot_order":           &hcldec.AttrSpec{Name: "legacy_gen1_boot_order", Type: cty.Bool, Required: false},
 		"shutdown_command":                 &hcldec.AttrSpec{Name: "shutdown_command", Type: cty.String, Required: false},
 		"shutdown_timeout":                 &hcldec.AttrSpec{Name: "shutdown_timeout", Type: cty.String, Required: false},
 		"disk_size":                        &hcldec.AttrSpec{Name: "disk_size", Type: cty.Number, Required: false},
diff --git a/builder/hyperv/vmcx/builder.hcl2spec.go b/builder/hyperv/vmcx/builder.hcl2spec.go
index 628436bf0..e2c028e73 100644
--- a/builder/hyperv/vmcx/builder.hcl2spec.go
+++ b/builder/hyperv/vmcx/builder.hcl2spec.go
@@ -97,6 +97,7 @@ type FlatConfig struct {
 	SkipCompaction                 *bool             `mapstructure:"skip_compaction" required:"false" cty:"skip_compaction"`
 	SkipExport                     *bool             `mapstructure:"skip_export" required:"false" cty:"skip_export"`
 	Headless                       *bool             `mapstructure:"headless" required:"false" cty:"headless"`
+	LegacyGen1BootOrder            *bool             `mapstructure:"legacy_gen1_boot_order" required:"false" cty:"legacy_gen1_boot_order"`
 	ShutdownCommand                *string           `mapstructure:"shutdown_command" required:"false" cty:"shutdown_command"`
 	ShutdownTimeout                *string           `mapstructure:"shutdown_timeout" required:"false" cty:"shutdown_timeout"`
 	CloneFromVMCXPath              *string           `mapstructure:"clone_from_vmcx_path" cty:"clone_from_vmcx_path"`
@@ -207,6 +208,7 @@ func (*FlatConfig) HCL2Spec() map[string]hcldec.Spec {
 		"skip_compaction":                  &hcldec.AttrSpec{Name: "skip_compaction", Type: cty.Bool, Required: false},
 		"skip_export":                      &hcldec.AttrSpec{Name: "skip_export", Type: cty.Bool, Required: false},
 		"headless":                         &hcldec.AttrSpec{Name: "headless", Type: cty.Bool, Required: false},
+		"legacy_gen1_boot_order":           &hcldec.AttrSpec{Name: "legacy_gen1_boot_order", Type: cty.Bool, Required: false},
 		"shutdown_command":                 &hcldec.AttrSpec{Name: "shutdown_command", Type: cty.String, Required: false},
 		"shutdown_timeout":                 &hcldec.AttrSpec{Name: "shutdown_timeout", Type: cty.String, Required: false},
 		"clone_from_vmcx_path":             &hcldec.AttrSpec{Name: "clone_from_vmcx_path", Type: cty.String, Required: false},
diff --git a/website/source/partials/builder/hyperv/common/_CommonConfig-not-required.html.md b/website/source/partials/builder/hyperv/common/_CommonConfig-not-required.html.md
index de742a737..e1ebf434b 100644
--- a/website/source/partials/builder/hyperv/common/_CommonConfig-not-required.html.md
+++ b/website/source/partials/builder/hyperv/common/_CommonConfig-not-required.html.md
@@ -109,4 +109,11 @@
     machines by launching a GUI that shows the console of the machine being
     built. When this value is set to true, the machine will start without a
     console.
+    
+-   `legacy_gen1_boot_order` (bool) - Over time the Hyper-V builder has been modified to change the original
+    boot order that is used when an ISO is mounted. Hyper-V's default is to
+    boot from the CD first, the original Hyper-V builder included code to
+    codify this setting when the primary ISO is mounted, that code was eventually
+    modified to place the IDE adapter before the the CD (only in generation 1).
+    Setting this value to true, forces the original method of operation.
     
\ No newline at end of file