diff --git a/codegen/nomwriter.go b/codegen/nomwriter.go
index a1f9a4ecba..14777ca0d8 100644
--- a/codegen/nomwriter.go
+++ b/codegen/nomwriter.go
@@ -36,6 +36,14 @@ func (nw *nomWriter) Write(w io.Writer, typ typewriter.Type) error {
 	if err != nil {
 		return err
 	}
+
+	w.Write([]byte(`
+// DO NOT EDIT
+//
+// This file was generated by a tool.
+// See http://clipperhouse.github.io/gen for details.
+`))
+
 	if err := tmpl.Execute(w, typ); err != nil {
 		return err
 	}
diff --git a/types/bool_noms.go b/types/bool_noms.go
index dd60ab202a..820e3f3af7 100644
--- a/types/bool_noms.go
+++ b/types/bool_noms.go
@@ -4,6 +4,11 @@
 
 package types
 
+// DO NOT EDIT
+//
+// This file was generated by a tool.
+// See http://clipperhouse.github.io/gen for details.
+
 func (self Bool) Equals(other Value) bool {
 	if other, ok := other.(Bool); ok {
 		return self == other
diff --git a/types/float32_noms.go b/types/float32_noms.go
index ff89200d41..fca728d685 100644
--- a/types/float32_noms.go
+++ b/types/float32_noms.go
@@ -4,6 +4,11 @@
 
 package types
 
+// DO NOT EDIT
+//
+// This file was generated by a tool.
+// See http://clipperhouse.github.io/gen for details.
+
 func (self Float32) Equals(other Value) bool {
 	if other, ok := other.(Float32); ok {
 		return self == other
diff --git a/types/float64_noms.go b/types/float64_noms.go
index fcf602d978..c061859b51 100644
--- a/types/float64_noms.go
+++ b/types/float64_noms.go
@@ -4,6 +4,11 @@
 
 package types
 
+// DO NOT EDIT
+//
+// This file was generated by a tool.
+// See http://clipperhouse.github.io/gen for details.
+
 func (self Float64) Equals(other Value) bool {
 	if other, ok := other.(Float64); ok {
 		return self == other
diff --git a/types/int16_noms.go b/types/int16_noms.go
index 45d1d5bc62..f4f5544a55 100644
--- a/types/int16_noms.go
+++ b/types/int16_noms.go
@@ -4,6 +4,11 @@
 
 package types
 
+// DO NOT EDIT
+//
+// This file was generated by a tool.
+// See http://clipperhouse.github.io/gen for details.
+
 func (self Int16) Equals(other Value) bool {
 	if other, ok := other.(Int16); ok {
 		return self == other
diff --git a/types/int32_noms.go b/types/int32_noms.go
index bda0f939dc..dc25811110 100644
--- a/types/int32_noms.go
+++ b/types/int32_noms.go
@@ -4,6 +4,11 @@
 
 package types
 
+// DO NOT EDIT
+//
+// This file was generated by a tool.
+// See http://clipperhouse.github.io/gen for details.
+
 func (self Int32) Equals(other Value) bool {
 	if other, ok := other.(Int32); ok {
 		return self == other
diff --git a/types/int64_noms.go b/types/int64_noms.go
index db64860585..0eeb5750ab 100644
--- a/types/int64_noms.go
+++ b/types/int64_noms.go
@@ -4,6 +4,11 @@
 
 package types
 
+// DO NOT EDIT
+//
+// This file was generated by a tool.
+// See http://clipperhouse.github.io/gen for details.
+
 func (self Int64) Equals(other Value) bool {
 	if other, ok := other.(Int64); ok {
 		return self == other
diff --git a/types/primitives.go b/types/primitives.go
index e4b69d1986..137382bf68 100644
--- a/types/primitives.go
+++ b/types/primitives.go
@@ -1,5 +1,8 @@
 package types
 
+// The methods for these types are generated by a tool.
+// See http://clipperhouse.github.io/gen.
+
 // +gen noms
 type Bool bool
 
diff --git a/types/uint16_noms.go b/types/uint16_noms.go
index f502f3ec4f..7f08e09076 100644
--- a/types/uint16_noms.go
+++ b/types/uint16_noms.go
@@ -4,6 +4,11 @@
 
 package types
 
+// DO NOT EDIT
+//
+// This file was generated by a tool.
+// See http://clipperhouse.github.io/gen for details.
+
 func (self UInt16) Equals(other Value) bool {
 	if other, ok := other.(UInt16); ok {
 		return self == other
diff --git a/types/uint32_noms.go b/types/uint32_noms.go
index 4461a0ce5a..dc85c045d0 100644
--- a/types/uint32_noms.go
+++ b/types/uint32_noms.go
@@ -4,6 +4,11 @@
 
 package types
 
+// DO NOT EDIT
+//
+// This file was generated by a tool.
+// See http://clipperhouse.github.io/gen for details.
+
 func (self UInt32) Equals(other Value) bool {
 	if other, ok := other.(UInt32); ok {
 		return self == other
diff --git a/types/uint64_noms.go b/types/uint64_noms.go
index 35cab152ba..3976d0be71 100644
--- a/types/uint64_noms.go
+++ b/types/uint64_noms.go
@@ -4,6 +4,11 @@
 
 package types
 
+// DO NOT EDIT
+//
+// This file was generated by a tool.
+// See http://clipperhouse.github.io/gen for details.
+
 func (self UInt64) Equals(other Value) bool {
 	if other, ok := other.(UInt64); ok {
 		return self == other