diff --git a/go.mod b/go.mod
index 2cd1c5bcaf..2e6a29e23c 100644
--- a/go.mod
+++ b/go.mod
@@ -83,7 +83,7 @@ require (
 
 require (
 	github.com/cenkalti/backoff/v5 v5.0.3 // indirect
-	github.com/fjl/jsonw v0.0.0-20260519133611-b234a3a62a01 // indirect
+	github.com/fjl/jsonw v0.0.0-20260519153618-cb1f61b11f55 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.7 // indirect
diff --git a/go.sum b/go.sum
index 9fa5364940..5c551ad909 100644
--- a/go.sum
+++ b/go.sum
@@ -131,6 +131,8 @@ github.com/fjl/jsonw v0.0.0-20260518201611-f2cd7df7ef66 h1:B+iPMRxXE3dbWXwQX6Un0
 github.com/fjl/jsonw v0.0.0-20260518201611-f2cd7df7ef66/go.mod h1:2KMLevM6FXEJnfhtk7naXu9vZdVfOma1GlnGdPRlumU=
 github.com/fjl/jsonw v0.0.0-20260519133611-b234a3a62a01 h1:2fvSvrrQMWs3l3MY1Ot4cPzv3Iww17ha1KJwjymX+Ks=
 github.com/fjl/jsonw v0.0.0-20260519133611-b234a3a62a01/go.mod h1:2KMLevM6FXEJnfhtk7naXu9vZdVfOma1GlnGdPRlumU=
+github.com/fjl/jsonw v0.0.0-20260519153618-cb1f61b11f55 h1:QH056XH5XG73Mr/f0BUFwNVsbRxauNDaSF1fBnIlF2Q=
+github.com/fjl/jsonw v0.0.0-20260519153618-cb1f61b11f55/go.mod h1:2KMLevM6FXEJnfhtk7naXu9vZdVfOma1GlnGdPRlumU=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4IgpuI1SZQ=
 github.com/fsnotify/fsnotify v1.6.0 h1:n+5WquG0fcWoWp6xPWfHdbskMCQaFnG6PfBrh1Ky4HY=
diff --git a/rpc/json.go b/rpc/json.go
index 120e6fa7c2..9813acae73 100644
--- a/rpc/json.go
+++ b/rpc/json.go
@@ -27,7 +27,8 @@ import (
 	"strings"
 	"sync"
 	"time"
-	"unicode/utf8"
+
+	"github.com/fjl/jsonw"
 )
 
 const (
@@ -257,7 +258,7 @@ func appendMessage(buf []byte, msg *jsonrpcMessage) []byte {
 	}
 	if msg.Method != "" {
 		buf = append(buf, `,"method":`...)
-		buf = appendQuotedString(buf, msg.Method)
+		buf = jsonw.AppendQuotedString(buf, msg.Method)
 	}
 	if msg.Params != nil {
 		buf = append(buf, `,"params":`...)
@@ -288,56 +289,6 @@ func appendBatch(buf []byte, msgs []*jsonrpcMessage) []byte {
 	return buf
 }
 
-const hexDigits = "0123456789abcdef"
-
-// appendQuotedString appends a JSON-quoted string to buf. Adapted
-// from encoding/json appendString without HTML and JSONP safety escaping.
-func appendQuotedString(buf []byte, s string) []byte {
-	buf = append(buf, '"')
-	start := 0
-	for i := 0; i < len(s); {
-		if b := s[i]; b < utf8.RuneSelf {
-			if b >= 0x20 && b != '\\' && b != '"' {
-				i++
-				continue
-			}
-			buf = append(buf, s[start:i]...)
-			switch b {
-			case '\\', '"':
-				buf = append(buf, '\\', b)
-			case '\b':
-				buf = append(buf, '\\', 'b')
-			case '\f':
-				buf = append(buf, '\\', 'f')
-			case '\n':
-				buf = append(buf, '\\', 'n')
-			case '\r':
-				buf = append(buf, '\\', 'r')
-			case '\t':
-				buf = append(buf, '\\', 't')
-			default:
-				// This encodes bytes < 0x20 except for \b, \f, \n, \r and \t.
-				buf = append(buf, '\\', 'u', '0', '0', hexDigits[b>>4], hexDigits[b&0xF])
-			}
-			i++
-			start = i
-			continue
-		}
-		c, size := utf8.DecodeRuneInString(s[i:])
-		if c == utf8.RuneError && size == 1 {
-			buf = append(buf, s[start:i]...)
-			buf = append(buf, `\ufffd`...)
-			i += size
-			start = i
-			continue
-		}
-		i += size
-	}
-	buf = append(buf, s[start:]...)
-	buf = append(buf, '"')
-	return buf
-}
-
 func (c *jsonCodec) peerInfo() PeerInfo {
 	// This returns "ipc" because all other built-in transports have a separate codec type.
 	return PeerInfo{Transport: "ipc", RemoteAddr: c.remote}