diff --git a/py/objstrunicode.c b/py/objstrunicode.c
index 0ee7f1d..062e011 100644
--- a/py/objstrunicode.c
+++ b/py/objstrunicode.c
@@ -91,41 +91,11 @@
     print(env, "%c", quote_char);
 }
 
-#if MICROPY_PY_UJSON
-STATIC void uni_print_json(void (*print)(void *env, const char *fmt, ...), void *env, const byte *str_data, uint str_len) {
-    print(env, "\"");
-    const byte *s = str_data, *top = str_data + str_len;
-    while (s < top) {
-        unichar ch;
-        ch = utf8_get_char(s);
-        s = utf8_next_char(s);
-        if (ch == '"' || ch == '\\' || ch == '/') {
-            print(env, "\\%c", ch);
-        } else if (32 <= ch && ch <= 126) {
-            print(env, "%c", ch);
-        } else if (*s == '\b') {
-            print(env, "\\b");
-        } else if (*s == '\f') {
-            print(env, "\\f");
-        } else if (*s == '\n') {
-            print(env, "\\n");
-        } else if (*s == '\r') {
-            print(env, "\\r");
-        } else if (*s == '\t') {
-            print(env, "\\t");
-        } else {
-            print(env, "\\u%04x", ch);
-        }
-    }
-    print(env, "\"");
-}
-#endif
-
 STATIC void uni_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
     GET_STR_DATA_LEN(self_in, str_data, str_len);
     #if MICROPY_PY_UJSON
     if (kind == PRINT_JSON) {
-        uni_print_json(print, env, str_data, str_len);
+        mp_str_print_json(print, env, str_data, str_len);
         return;
     }
     #endif