diff --git a/src/encoding/json/encode.go b/src/encoding/json/encode.go
index 38b98a57f7..9ba717c9ce 100644
--- a/src/encoding/json/encode.go
+++ b/src/encoding/json/encode.go
@@ -969,6 +969,10 @@ func appendString[Bytes []byte | string](dst []byte, src Bytes, escapeHTML bool)
 			switch b {
 			case '\\', '"':
 				dst = append(dst, '\\', b)
+			case '\b':
+				dst = append(dst, '\\', 'b')
+			case '\f':
+				dst = append(dst, '\\', 'f')
 			case '\n':
 				dst = append(dst, '\\', 'n')
 			case '\r':
diff --git a/src/encoding/json/encode_test.go b/src/encoding/json/encode_test.go
index d027972d8a..7972348801 100644
--- a/src/encoding/json/encode_test.go
+++ b/src/encoding/json/encode_test.go
@@ -113,7 +113,7 @@ func TestRoundtripStringTag(t *testing.T) {
 				"BoolStr": "false",
 				"IntStr": "0",
 				"UintptrStr": "0",
-				"StrStr": "\"\\u0008\\u000c\\n\\r\\t\\\"\\\\\"",
+				"StrStr": "\"\\b\\f\\n\\r\\t\\\"\\\\\"",
 				"NumberStr": "0"
 			}`,
 		},
@@ -795,11 +795,11 @@ var encodeStringTests = []struct {
 	{"\x05", `"\u0005"`},
 	{"\x06", `"\u0006"`},
 	{"\x07", `"\u0007"`},
-	{"\x08", `"\u0008"`},
+	{"\x08", `"\b"`},
 	{"\x09", `"\t"`},
 	{"\x0a", `"\n"`},
 	{"\x0b", `"\u000b"`},
-	{"\x0c", `"\u000c"`},
+	{"\x0c", `"\f"`},
 	{"\x0d", `"\r"`},
 	{"\x0e", `"\u000e"`},
 	{"\x0f", `"\u000f"`},