diff --git a/cc/makevars.go b/cc/makevars.go
index fe3440c..af4ba28 100644
--- a/cc/makevars.go
+++ b/cc/makevars.go
@@ -64,6 +64,8 @@
 	ctx.Strict("DEFAULT_LOCAL_TIDY_CHECKS", joinLocalTidyChecks(config.DefaultLocalTidyChecks))
 	ctx.Strict("DEFAULT_TIDY_HEADER_DIRS", "${config.TidyDefaultHeaderDirs}")
 
+	ctx.Strict("AIDL_CPP", "${aidlCmd}")
+
 	includeFlags, err := ctx.Eval("${config.CommonGlobalIncludes} ${config.CommonGlobalSystemIncludes}")
 	if err != nil {
 		panic(err)