diff --git a/src/special/London.tsx b/src/special/London.tsx
index 77b48cc..65e7ba4 100644
--- a/src/special/London.tsx
+++ b/src/special/London.tsx
@@ -3,22 +3,29 @@ import { useLatestBlock } from "../useLatestBlock";
 import { RuntimeContext } from "../useRuntime";
 import Countdown from "./Countdown";
 
-const londonBlockNumber = 12965000;
+const londonBlockNumber: { [chainId: string]: number } = {
+  "1": 12965000,
+  "3": 10499401,
+  "4": 8897988,
+  "5": 5062605,
+};
 
 const London: React.FC = () => {
   const { provider } = useContext(RuntimeContext);
   const block = useLatestBlock(provider);
-  if (!block) {
+  if (!provider || !block) {
     return <></>;
   }
 
   // Display countdown
-  if (provider && block.number < londonBlockNumber) {
+  const targetBlockNumber =
+    londonBlockNumber[provider.network.chainId.toString()];
+  if (block.number < targetBlockNumber) {
     return (
       <Countdown
         provider={provider}
         currentBlock={block}
-        targetBlock={londonBlockNumber}
+        targetBlock={targetBlockNumber}
       />
     );
   }