diff --git a/domains/TdoubleT.is-a-fullstack.dev.json b/domains/tdoublet.is-a-fullstack.dev.json
similarity index 89%
rename from domains/TdoubleT.is-a-fullstack.dev.json
rename to domains/tdoublet.is-a-fullstack.dev.json
index 10b430aa..1a0b6851 100644
--- a/domains/TdoubleT.is-a-fullstack.dev.json
+++ b/domains/tdoublet.is-a-fullstack.dev.json
@@ -1,6 +1,6 @@
 {
     "domain": "is-a-fullstack.dev",
-    "subdomain": "TdoubleT",
+    "subdomain": "tdoublet",
 
     "owner": {
         "repo": "https://github.com/tuanthu1/tuanthu2",