diff --git a/parson.c b/parson.c
index fc7621f..a2cc438 100644
--- a/parson.c
+++ b/parson.c
@@ -911,6 +911,38 @@ static int json_serialize_string(const char *string, char *buf) {
             case '\n': APPEND_STRING("\\n"); break;
             case '\r': APPEND_STRING("\\r"); break;
             case '\t': APPEND_STRING("\\t"); break;
+            case '\x00': APPEND_STRING("\\u0000"); break;
+            case '\x01': APPEND_STRING("\\u0001"); break;
+            case '\x02': APPEND_STRING("\\u0002"); break;
+            case '\x03': APPEND_STRING("\\u0003"); break;
+            case '\x04': APPEND_STRING("\\u0004"); break;
+            case '\x05': APPEND_STRING("\\u0005"); break;
+            case '\x06': APPEND_STRING("\\u0006"); break;
+            case '\x07': APPEND_STRING("\\u0007"); break;
+            /* '\x08' duplicate: '\b' */
+            /* '\x09' duplicate: '\t' */
+            /* '\x0a' duplicate: '\n' */
+            case '\x0b': APPEND_STRING("\\u000b"); break;
+            /* '\x0c' duplicate: '\f' */
+            /* '\x0d' duplicate: '\r' */
+            case '\x0e': APPEND_STRING("\\u000e"); break;
+            case '\x0f': APPEND_STRING("\\u000f"); break;
+            case '\x10': APPEND_STRING("\\u0010"); break;
+            case '\x11': APPEND_STRING("\\u0011"); break;
+            case '\x12': APPEND_STRING("\\u0012"); break;
+            case '\x13': APPEND_STRING("\\u0013"); break;
+            case '\x14': APPEND_STRING("\\u0014"); break;
+            case '\x15': APPEND_STRING("\\u0015"); break;
+            case '\x16': APPEND_STRING("\\u0016"); break;
+            case '\x17': APPEND_STRING("\\u0017"); break;
+            case '\x18': APPEND_STRING("\\u0018"); break;
+            case '\x19': APPEND_STRING("\\u0019"); break;
+            case '\x1a': APPEND_STRING("\\u001a"); break;
+            case '\x1b': APPEND_STRING("\\u001b"); break;
+            case '\x1c': APPEND_STRING("\\u001c"); break;
+            case '\x1d': APPEND_STRING("\\u001d"); break;
+            case '\x1e': APPEND_STRING("\\u001e"); break;
+            case '\x1f': APPEND_STRING("\\u001f"); break;
             default:
                 if (buf != NULL) {
                     buf[0] = c;