diff --git a/packages/providers/src.ts/json-rpc-provider.ts b/packages/providers/src.ts/json-rpc-provider.ts
index 3b3df2289..6caab7052 100644
--- a/packages/providers/src.ts/json-rpc-provider.ts
+++ b/packages/providers/src.ts/json-rpc-provider.ts
@@ -640,8 +640,8 @@ export class JsonRpcProvider extends BaseProvider {
 
         const result: { [key: string]: string | AccessList } = {};
 
-        // Some nodes (INFURA ropsten; INFURA mainnet is fine) do not like leading zeros.
-        ["gasLimit", "gasPrice", "type", "maxFeePerGas", "maxPriorityFeePerGas", "nonce", "value"].forEach(function(key) {
+        // JSON-RPC now requires numeric values to be "quantity" values
+        ["chainId", "gasLimit", "gasPrice", "type", "maxFeePerGas", "maxPriorityFeePerGas", "nonce", "value"].forEach(function(key) {
             if ((<any>transaction)[key] == null) { return; }
             const value = hexValue((<any>transaction)[key]);
             if (key === "gasLimit") { key = "gas"; }