diff --git a/genkeys.go b/genkeys.go
index 187d5709d..7afc37d4b 100644
--- a/genkeys.go
+++ b/genkeys.go
@@ -249,8 +249,8 @@ type Key int
 
 // Keys.
 const (
-{{range $index, $name := .KeyNames}}Key{{$name}} Key = Key(driver.Key{{$name}})
-{{end}}	KeyMax Key = Key{{.LastKeyName}}
+{{range $index, $name := .EbitenKeyNames}}Key{{$name}} Key = Key(driver.Key{{$name}})
+{{end}}	KeyMax Key = Key{{.LastEbitenKeyName}}
 )
 
 // String returns a string representing the key.
@@ -258,7 +258,7 @@ const (
 // If k is an undefined key, String returns an empty string.
 func (k Key) String() string {
 	switch k {
-	{{range $name := .KeyNames}}case Key{{$name}}:
+	{{range $name := .EbitenKeyNames}}case Key{{$name}}:
 		return {{$name | printf "%q"}}
 	{{end}}}
 	return ""
@@ -266,7 +266,7 @@ func (k Key) String() string {
 
 func keyNameToKey(name string) (Key, bool) {
 	switch strings.ToLower(name) {
-	{{range $name := .KeyNames}}case {{$name | printf "%q" | ToLower}}:
+	{{range $name := .EbitenKeyNames}}case {{$name | printf "%q" | ToLower}}:
 		return Key{{$name}}, true
 	{{end}}}
 	return 0, false
@@ -282,7 +282,7 @@ package driver
 type Key int
 
 const (
-{{range $index, $name := .KeyNames}}Key{{$name}}{{if eq $index 0}} Key = iota{{end}}
+{{range $index, $name := .EbitenKeyNames}}Key{{$name}}{{if eq $index 0}} Key = iota{{end}}
 {{end}}
 )
 `
@@ -301,7 +301,7 @@ import (
 )
 
 var glfwKeyCodeToKey = map[glfw.Key]driver.Key{
-{{range $index, $name := .KeyNamesWithoutMods}}glfw.Key{{$name}}: driver.Key{{$name}},
+{{range $index, $name := .EbitenKeyNamesWithoutMods}}glfw.Key{{$name}}: driver.Key{{$name}},
 {{end}}
 	glfw.KeyLeftAlt:      driver.KeyAlt,
 	glfw.KeyRightAlt:     driver.KeyAlt,
@@ -440,28 +440,17 @@ func main() {
 	// Follow the standard comment rule (https://golang.org/s/generatedcode).
 	doNotEdit := "// Code generated by genkeys.go using 'go generate'. DO NOT EDIT."
 
-	namesSet := map[string]struct{}{}
-	namesWithoutModsSet := map[string]struct{}{}
-	codes := []string{}
-	for name, cs := range nameToJSKeyCodes {
-		namesSet[name] = struct{}{}
-		codes = append(codes, cs...)
+	ebitenKeyNames := []string{}
+	ebitenKeyNamesWithoutMods := []string{}
+	for name := range nameToJSKeyCodes {
+		ebitenKeyNames = append(ebitenKeyNames, name)
 		if name != "Alt" && name != "Control" && name != "Shift" {
-			namesWithoutModsSet[name] = struct{}{}
+			ebitenKeyNamesWithoutMods = append(ebitenKeyNamesWithoutMods, name)
 		}
 	}
-	names := []string{}
-	namesWithoutMods := []string{}
-	for n := range namesSet {
-		names = append(names, n)
-	}
-	for n := range namesWithoutModsSet {
-		namesWithoutMods = append(namesWithoutMods, n)
-	}
 
-	sort.Slice(names, keyNamesLess(names))
-	sort.Slice(namesWithoutMods, keyNamesLess(namesWithoutMods))
-	sort.Strings(codes)
+	sort.Slice(ebitenKeyNames, keyNamesLess(ebitenKeyNames))
+	sort.Slice(ebitenKeyNamesWithoutMods, keyNamesLess(ebitenKeyNamesWithoutMods))
 
 	for path, tmpl := range map[string]string{
 		"keys.go":                        ebitenKeysTmpl,
@@ -498,27 +487,25 @@ func main() {
 		}
 		// NOTE: According to godoc, maps are automatically sorted by key.
 		if err := tmpl.Execute(f, struct {
-			License             string
-			DoNotEdit           string
-			BuildTag            string
-			NameToJSKeyCodes    map[string][]string
-			KeyCodeToNameEdge   map[int]string
-			Codes               []string
-			KeyNames            []string
-			LastKeyName         string
-			KeyNamesWithoutMods []string
-			NameToGLFWKeys      map[string]glfw.Key
+			License                   string
+			DoNotEdit                 string
+			BuildTag                  string
+			NameToJSKeyCodes          map[string][]string
+			KeyCodeToNameEdge         map[int]string
+			EbitenKeyNames            []string
+			EbitenKeyNamesWithoutMods []string
+			LastEbitenKeyName         string
+			NameToGLFWKeys            map[string]glfw.Key
 		}{
-			License:             license,
-			DoNotEdit:           doNotEdit,
-			BuildTag:            buildTag,
-			NameToJSKeyCodes:    nameToJSKeyCodes,
-			KeyCodeToNameEdge:   keyCodeToNameEdge,
-			Codes:               codes,
-			KeyNames:            names,
-			LastKeyName:         names[len(names)-1],
-			KeyNamesWithoutMods: namesWithoutMods,
-			NameToGLFWKeys:      nameToGLFWKeys,
+			License:                   license,
+			DoNotEdit:                 doNotEdit,
+			BuildTag:                  buildTag,
+			NameToJSKeyCodes:          nameToJSKeyCodes,
+			KeyCodeToNameEdge:         keyCodeToNameEdge,
+			EbitenKeyNames:            ebitenKeyNames,
+			EbitenKeyNamesWithoutMods: ebitenKeyNamesWithoutMods,
+			LastEbitenKeyName:         ebitenKeyNames[len(ebitenKeyNames)-1],
+			NameToGLFWKeys:            nameToGLFWKeys,
 		}); err != nil {
 			log.Fatal(err)
 		}