diff --git a/docs/reference/api/json-rpc.md b/docs/reference/api/json-rpc.md
index cff882e..21516f9 100644
--- a/docs/reference/api/json-rpc.md
+++ b/docs/reference/api/json-rpc.md
@@ -147,6 +147,8 @@ curl -X POST --data '{"jsonrpc":"2.0","method":"eth_signTransaction","params":[{
 `eth_signTypedData` is the same as `ethsign` except a typed data structure is specified
 as the object to be signed instead of a data string.
 
+The object to be signed must be serialized to a string before calling this method.
+
 Calculates an Ethereum specific signature using
 `sign(keccak256("\x19Ethereum Signed Message:\n" + len(message) + message)))."`
 
@@ -204,7 +206,7 @@ The JSON schema for the typed data structure to sign is:
   <TabItem value="curl HTTP request" label="curl HTTP request" default>
 
 ```bash
-curl -X POST --data '{"jsonrpc":"2.0","method":"eth_signTypedData","params":["0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826", {"types":{"EIP712Domain":[{"name":"name","type":"string"},{"name":"version","type":"string"},{"name":"chainId","type":"uint256"},{"name":"verifyingContract","type":"address"}],"Person":[{"name":"name","type":"string"},{"name":"wallet","type":"address"}],"Mail":[{"name":"from","type":"Person"},{"name":"to","type":"Person"},{"name":"contents","type":"string"}]},"primaryType":"Mail","domain":{"name":"Ether Mail","version":"1","chainId":1,"verifyingContract":"0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC"},"message":{"from":{"name":"Cow","wallet":"0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826"},"to":{"name":"Bob","wallet":"0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB"},"contents":"Hello, Bob!"}}],"id":1}'
+curl -X POST --data '{"jsonrpc":"2.0","method":"eth_signTypedData","params":["0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826", "{\"types\":{\"EIP712Domain\":[{\"name\":\"name\",\"type\":\"string\"},{\"name\":\"version\",\"type\":\"string\"},{\"name\":\"chainId\",\"type\":\"uint256\"},{\"name\":\"verifyingContract\",\"type\":\"address\"}],\"Person\":[{\"name\":\"name\",\"type\":\"string\"},{\"name\":\"wallet\",\"type\":\"address\"}],\"Mail\":[{\"name\":\"from\",\"type\":\"Person\"},{\"name\":\"to\",\"type\":\"Person\"},{\"name\":\"contents\",\"type\":\"string\"}]},\"primaryType\":\"Mail\",\"domain\":{\"name\":\"Ether Mail\",\"version\":\"1\",\"chainId\":\"31337\",\"verifyingContract\":\"0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC\"},\"message\":{\"from\":{\"name\":\"Cow\",\"wallet\":\"0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826\"},\"to\":{\"name\":\"Bob\",\"wallet\":\"0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB\"},\"contents\":\"Hello, Bob!\"}}"],"id":1}'
 ```
 
   </TabItem>