diff --git a/client/Cargo.toml b/client/Cargo.toml
index a9ff7ec3..65049ef4 100644
--- a/client/Cargo.toml
+++ b/client/Cargo.toml
@@ -22,7 +22,7 @@ path = "src/lib.rs"
 bitcoincore-rpc-json = { version = "0.18.0", path = "../json" }
 
 log = "0.4.5"
-jsonrpc = "0.14.0"
+jsonrpc = { version = "0.18.0", features = [] }
 
 # Used for deserialization of JSON.
 serde = "1"
diff --git a/client/src/client.rs b/client/src/client.rs
index c97a0174..2f809a79 100644
--- a/client/src/client.rs
+++ b/client/src/client.rs
@@ -1313,12 +1313,8 @@ impl RpcApi for Client {
         cmd: &str,
         args: &[serde_json::Value],
     ) -> Result<T> {
-        let raw_args: Vec<_> = args
-            .iter()
-            .map(serde_json::value::to_raw_value)
-            .map(|a| a.map_err(|e| Error::Json(e)))
-            .collect::<Result<Vec<_>>>()?;
-        let req = self.client.build_request(&cmd, &raw_args);
+        let raw = serde_json::value::to_raw_value(args)?;
+        let req = self.client.build_request(&cmd, Some(&*raw));
         if log_enabled!(Debug) {
             debug!(target: "bitcoincore_rpc", "JSON-RPC request: {} {}", cmd, serde_json::Value::from(args));
         }