diff --git a/.changeset/chilly-vans-pay.md b/.changeset/chilly-vans-pay.md
new file mode 100644
index 0000000000..1d9ee3a501
--- /dev/null
+++ b/.changeset/chilly-vans-pay.md
@@ -0,0 +1,5 @@
+---
+"viem": patch
+---
+
+add rns registry contract address
diff --git a/src/chains/definitions/rootstock.ts b/src/chains/definitions/rootstock.ts
index a60c139c34..5c3d1c3465 100644
--- a/src/chains/definitions/rootstock.ts
+++ b/src/chains/definitions/rootstock.ts
@@ -18,7 +18,11 @@ export const rootstock = /*#__PURE__*/ defineChain({
       url: 'https://explorer.rsk.co',
     },
   },
+  ensTlds: ['.rsk'],
   contracts: {
+    ensRegistry: {
+      address: '0xcb868aeabd31e2b66f74e9a55cf064abb31a4ad5',
+    },
     multicall3: {
       address: '0xcA11bde05977b3631167028862bE2a173976CA11',
       blockCreated: 4249540,