diff --git a/.changeset/nasty-doors-wash.md b/.changeset/nasty-doors-wash.md
new file mode 100644
index 0000000000..cdc097abb2
--- /dev/null
+++ b/.changeset/nasty-doors-wash.md
@@ -0,0 +1,5 @@
+---
+"viem": patch
+---
+
+update celo alfajores chain to include op contract addresses
diff --git a/src/celo/chainConfig.ts b/src/celo/chainConfig.ts
index 2049911857..7ab857367a 100644
--- a/src/celo/chainConfig.ts
+++ b/src/celo/chainConfig.ts
@@ -1,8 +1,10 @@
+import { contracts } from '../op-stack/contracts.js'
 import { fees } from './fees.js'
 import { formatters } from './formatters.js'
 import { serializers } from './serializers.js'
 
 export const chainConfig = {
+  contracts,
   formatters,
   serializers,
   fees,
diff --git a/src/chains/definitions/celoAlfajores.ts b/src/chains/definitions/celoAlfajores.ts
index e87254e7e5..11aec6b710 100644
--- a/src/chains/definitions/celoAlfajores.ts
+++ b/src/chains/definitions/celoAlfajores.ts
@@ -1,6 +1,8 @@
 import { chainConfig } from '../../celo/chainConfig.js'
 import { defineChain } from '../../utils/chain/defineChain.js'
 
+const sourceId = 11_155_111 // sepolia
+
 export const celoAlfajores = /*#__PURE__*/ defineChain({
   ...chainConfig,
   id: 44_787,
@@ -23,10 +25,36 @@ export const celoAlfajores = /*#__PURE__*/ defineChain({
     },
   },
   contracts: {
+    ...chainConfig.contracts,
     multicall3: {
       address: '0xcA11bde05977b3631167028862bE2a173976CA11',
       blockCreated: 14569001,
     },
+    portal: {
+      [sourceId]: {
+        address: '0x969d247cB586C0bF02212B9ae6e690e8b0d762bA',
+      },
+    },
+    disputeGameFactory: {
+      [sourceId]: {
+        address: '0xB0C46509E24a0745d201114016fD666D6D1E3f8e',
+      },
+    },
+    l2OutputOracle: {
+      [sourceId]: {
+        address: '0x58eeeEC56C6e92b1898367fa7372ab3f6483F054',
+      },
+    },
+    l1StandardBridge: {
+      [sourceId]: {
+        address: '0x65E8f629B13535f902020668Fe73aEc24e52F5D8',
+      },
+    },
+    l2StandardBridge: {
+      [sourceId]: {
+        address: '0x4200000000000000000000000000000000000010',
+      },
+    },
   },
   testnet: true,
 })