diff --git a/cc/makevars.go b/cc/makevars.go
index fb567ba..d91735f 100644
--- a/cc/makevars.go
+++ b/cc/makevars.go
@@ -24,24 +24,24 @@
 	"android/soong/cc/config"
 )
 
-const (
-	modulesAddedWall          = "ModulesAddedWall"
-	modulesUsingWnoError      = "ModulesUsingWnoError"
-	modulesMissingProfileFile = "ModulesMissingProfileFile"
+var (
+	modulesAddedWallKey          = android.NewOnceKey("ModulesAddedWall")
+	modulesUsingWnoErrorKey      = android.NewOnceKey("ModulesUsingWnoError")
+	modulesMissingProfileFileKey = android.NewOnceKey("ModulesMissingProfileFile")
 )
 
 func init() {
 	android.RegisterMakeVarsProvider(pctx, makeVarsProvider)
 }
 
-func getNamedMapForConfig(config android.Config, name string) *sync.Map {
-	return config.Once(name, func() interface{} {
+func getNamedMapForConfig(config android.Config, key android.OnceKey) *sync.Map {
+	return config.Once(key, func() interface{} {
 		return &sync.Map{}
 	}).(*sync.Map)
 }
 
-func makeStringOfKeys(ctx android.MakeVarsContext, setName string) string {
-	set := getNamedMapForConfig(ctx.Config(), setName)
+func makeStringOfKeys(ctx android.MakeVarsContext, key android.OnceKey) string {
+	set := getNamedMapForConfig(ctx.Config(), key)
 	keys := []string{}
 	set.Range(func(key interface{}, value interface{}) bool {
 		keys = append(keys, key.(string))
@@ -117,9 +117,9 @@
 	ctx.Strict("LSDUMP_PATHS", strings.Join(lsdumpPaths, " "))
 
 	ctx.Strict("ANDROID_WARNING_ALLOWED_PROJECTS", makeStringOfWarningAllowedProjects())
-	ctx.Strict("SOONG_MODULES_ADDED_WALL", makeStringOfKeys(ctx, modulesAddedWall))
-	ctx.Strict("SOONG_MODULES_USING_WNO_ERROR", makeStringOfKeys(ctx, modulesUsingWnoError))
-	ctx.Strict("SOONG_MODULES_MISSING_PGO_PROFILE_FILE", makeStringOfKeys(ctx, modulesMissingProfileFile))
+	ctx.Strict("SOONG_MODULES_ADDED_WALL", makeStringOfKeys(ctx, modulesAddedWallKey))
+	ctx.Strict("SOONG_MODULES_USING_WNO_ERROR", makeStringOfKeys(ctx, modulesUsingWnoErrorKey))
+	ctx.Strict("SOONG_MODULES_MISSING_PGO_PROFILE_FILE", makeStringOfKeys(ctx, modulesMissingProfileFileKey))
 
 	ctx.Strict("ADDRESS_SANITIZER_CONFIG_EXTRA_CFLAGS", strings.Join(asanCflags, " "))
 	ctx.Strict("ADDRESS_SANITIZER_CONFIG_EXTRA_LDFLAGS", strings.Join(asanLdflags, " "))