diff --git a/gen/function_source.c b/gen/function_source.c
index f012209..85705da 100644
Binary files a/gen/function_source.c and b/gen/function_source.c differ
diff --git a/gen/hello.c b/gen/hello.c
index 6389825..e131cfa 100644
Binary files a/gen/hello.c and b/gen/hello.c differ
diff --git a/gen/hello_module.c b/gen/hello_module.c
index be72121..98a6765 100644
Binary files a/gen/hello_module.c and b/gen/hello_module.c differ
diff --git a/gen/repl.c b/gen/repl.c
index 8e33106..9bdd1f8 100644
Binary files a/gen/repl.c and b/gen/repl.c differ
diff --git a/gen/test_fib.c b/gen/test_fib.c
index d37dd9f..53c431b 100644
Binary files a/gen/test_fib.c and b/gen/test_fib.c differ
diff --git a/quickjs.c b/quickjs.c
index 527fea8..a1fc361 100644
--- a/quickjs.c
+++ b/quickjs.c
@@ -33114,9 +33114,11 @@ typedef enum BCTagEnum {
     BC_TAG_DATE,
     BC_TAG_OBJECT_VALUE,
     BC_TAG_OBJECT_REFERENCE,
+    BC_TAG_MAP,
+    BC_TAG_SET,
 } BCTagEnum;
 
-#define BC_VERSION 12
+#define BC_VERSION 13
 
 typedef struct BCWriterState {
     JSContext *ctx;
@@ -33757,6 +33759,9 @@ static int JS_WriteRegExp(BCWriterState *s, JSRegExp regexp)
     return 0;
 }
 
+static int JS_WriteMap(BCWriterState *s, struct JSMapState *map_state);
+static int JS_WriteSet(BCWriterState *s, struct JSMapState *map_state);
+
 static int JS_WriteObjectRec(BCWriterState *s, JSValue obj)
 {
     uint32_t tag;
@@ -33860,6 +33865,14 @@ static int JS_WriteObjectRec(BCWriterState *s, JSValue obj)
                 bc_put_u8(s, BC_TAG_OBJECT_VALUE);
                 ret = JS_WriteObjectRec(s, p->u.object_data);
                 break;
+            case JS_CLASS_MAP:
+                bc_put_u8(s, BC_TAG_MAP);
+                ret = JS_WriteMap(s, p->u.map_state);
+                break;
+            case JS_CLASS_SET:
+                bc_put_u8(s, BC_TAG_SET);
+                ret = JS_WriteSet(s, p->u.map_state);
+                break;
             default:
                 if (p->class_id >= JS_CLASS_UINT8C_ARRAY &&
                     p->class_id <= JS_CLASS_FLOAT64_ARRAY) {
@@ -34996,6 +35009,9 @@ static JSValue JS_ReadObjectValue(BCReaderState *s)
     return JS_EXCEPTION;
 }
 
+static JSValue JS_ReadMap(BCReaderState *s);
+static JSValue JS_ReadSet(BCReaderState *s);
+
 static JSValue JS_ReadObjectRec(BCReaderState *s)
 {
     JSContext *ctx = s->ctx;
@@ -35103,6 +35119,12 @@ static JSValue JS_ReadObjectRec(BCReaderState *s)
             obj = js_dup(JS_MKPTR(JS_TAG_OBJECT, s->objects[val]));
         }
         break;
+    case BC_TAG_MAP:
+        obj = JS_ReadMap(s);
+        break;
+    case BC_TAG_SET:
+        obj = JS_ReadSet(s);
+        break;
     default:
     invalid_tag:
         return JS_ThrowSyntaxError(ctx, "invalid tag (tag=%d pos=%u)",
@@ -46026,6 +46048,99 @@ static JSValue js_map_iterator_next(JSContext *ctx, JSValue this_val,
     }
 }
 
+static JSValue js_map_read(BCReaderState *s, int magic)
+{
+    JSContext *ctx = s->ctx;
+    JSValue obj, rv, argv[2];
+    uint32_t i, prop_count;
+
+    argv[0] = JS_UNDEFINED;
+    argv[1] = JS_UNDEFINED;
+    obj = js_map_constructor(ctx, JS_UNDEFINED, 0, NULL, magic);
+    if (JS_IsException(obj))
+        return JS_EXCEPTION;
+    if (BC_add_object_ref(s, obj))
+        goto fail;
+    if (bc_get_leb128(s, &prop_count))
+        goto fail;
+    for(i = 0; i < prop_count; i++) {
+        argv[0] = JS_ReadObjectRec(s);
+        if (JS_IsException(argv[0]))
+            goto fail;
+        if (!(magic & MAGIC_SET)) {
+            argv[1] = JS_ReadObjectRec(s);
+            if (JS_IsException(argv[1]))
+                goto fail;
+        }
+        rv = js_map_set(ctx, obj, countof(argv), argv, magic);
+        if (JS_IsException(rv))
+            goto fail;
+        JS_FreeValue(ctx, rv);
+        JS_FreeValue(ctx, argv[0]);
+        JS_FreeValue(ctx, argv[1]);
+        argv[0] = JS_UNDEFINED;
+        argv[1] = JS_UNDEFINED;
+    }
+    return obj;
+ fail:
+    JS_FreeValue(ctx, obj);
+    JS_FreeValue(ctx, argv[0]);
+    JS_FreeValue(ctx, argv[1]);
+    return JS_EXCEPTION;
+}
+
+static int js_map_write(BCWriterState *s, struct JSMapState *map_state,
+                        int magic)
+{
+    struct list_head *el;
+    JSMapRecord *mr;
+    uint32_t count;
+
+    count = 0;
+
+    if (map_state) {
+        list_for_each(el, &map_state->records) {
+            count++;
+        }
+    }
+
+    bc_put_leb128(s, count);
+
+    if (map_state) {
+        list_for_each(el, &map_state->records) {
+            mr = list_entry(el, JSMapRecord, link);
+            if (JS_WriteObjectRec(s, mr->key))
+                return -1;
+            // mr->value is always JS_UNDEFINED for sets
+            if (!(magic & MAGIC_SET))
+                if (JS_WriteObjectRec(s, mr->value))
+                    return -1;
+        }
+    }
+
+    return 0;
+}
+
+static JSValue JS_ReadMap(BCReaderState *s)
+{
+    return js_map_read(s, 0);
+}
+
+static JSValue JS_ReadSet(BCReaderState *s)
+{
+    return js_map_read(s, MAGIC_SET);
+}
+
+static int JS_WriteMap(BCWriterState *s, struct JSMapState *map_state)
+{
+    return js_map_write(s, map_state, 0);
+}
+
+static int JS_WriteSet(BCWriterState *s, struct JSMapState *map_state)
+{
+    return js_map_write(s, map_state, MAGIC_SET);
+}
+
 static const JSCFunctionListEntry js_map_funcs[] = {
     JS_CFUNC_DEF("groupBy", 2, js_map_groupBy ),
     JS_CGETSET_DEF("[Symbol.species]", js_get_this, NULL ),
diff --git a/tests/test_bjson.js b/tests/test_bjson.js
index 685ec1c..e12919b 100644
--- a/tests/test_bjson.js
+++ b/tests/test_bjson.js
@@ -155,6 +155,28 @@ function bjson_test_regexp()
     assert("sup dog".match(r).groups["𝓓𝓸𝓰"], "dog");
 }
 
+function bjson_test_map()
+{
+    var buf, r, xs;
+
+    xs = [["key", "value"]];
+    buf = bjson.write(new Map(xs));
+    r = bjson.read(buf, 0, buf.byteLength);
+    assert(r instanceof Map);
+    assert([...r].toString(), xs.toString());
+}
+
+function bjson_test_set()
+{
+    var buf, r, xs;
+
+    xs = ["one", "two", "three"];
+    buf = bjson.write(new Set(xs));
+    r = bjson.read(buf, 0, buf.byteLength);
+    assert(r instanceof Set);
+    assert([...r].toString(), xs.toString());
+}
+
 function bjson_test_all()
 {
     var obj;
@@ -184,6 +206,8 @@ function bjson_test_all()
 
     bjson_test_reference();
     bjson_test_regexp();
+    bjson_test_map();
+    bjson_test_set();
 }
 
 bjson_test_all();