diff --git a/upb/json/parser.c b/upb/json/parser.c
index d8db7fead6..b8b832edbe 100644
--- a/upb/json/parser.c
+++ b/upb/json/parser.c
@@ -186,6 +186,11 @@ typedef struct {
   /* The table mapping json name to fielddef for this message. */
   const upb_strtable *name_table;
 
+  /* We are in a repeated-field context. We need this flag to decide whether to
+   * handle the array as a normal repeated field or a
+   * google.protobuf.ListValue/google.protobuf.Value. */
+  bool is_repeated;
+
   /* We are in a repeated-field context, ready to emit mapentries as
    * submessages. This flag alters the start-of-object (open-brace) behavior to
    * begin a sequence of mapentry messages rather than a single submessage. */
@@ -216,6 +221,19 @@ typedef struct {
   bool is_unknown_field;
 } upb_jsonparser_frame;
 
+static void init_frame(upb_jsonparser_frame* frame) {
+  frame->m = NULL;
+  frame->f = NULL;
+  frame->name_table = NULL;
+  frame->is_repeated = false;
+  frame->is_map = false;
+  frame->is_mapentry = false;
+  frame->mapfield = NULL;
+  frame->is_any = false;
+  frame->any_frame = NULL;
+  frame->is_unknown_field = false;
+}
+
 struct upb_json_parser {
   upb_arena *arena;
   const upb_json_parsermethod *method;
@@ -263,6 +281,13 @@ struct upb_json_parser {
   struct tm tm;
 };
 
+static upb_jsonparser_frame* start_jsonparser_frame(upb_json_parser *p) {
+  upb_jsonparser_frame *inner;
+  inner = p->top + 1;
+  init_frame(inner);
+  return inner;
+}
+
 struct upb_json_codecache {
   upb_arena *arena;
   upb_inttable methods;   /* upb_msgdef* -> upb_json_parsermethod* */
@@ -1221,17 +1246,11 @@ static bool start_stringval(upb_json_parser *p) {
 
     /* Start a new parser frame: parser frames correspond one-to-one with
      * handler frames, and string events occur in a sub-frame. */
-    inner = p->top + 1;
+    inner = start_jsonparser_frame(p);
     sel = getsel_for_handlertype(p, UPB_HANDLER_STARTSTR);
     upb_sink_startstr(p->top->sink, sel, 0, &inner->sink);
     inner->m = p->top->m;
     inner->f = p->top->f;
-    inner->name_table = NULL;
-    inner->is_map = false;
-    inner->is_mapentry = false;
-    inner->is_any = false;
-    inner->any_frame = NULL;
-    inner->is_unknown_field = false;
     p->top = inner;
 
     if (upb_fielddef_type(p->top->f) == UPB_TYPE_STRING) {
@@ -1686,17 +1705,11 @@ static bool start_fieldmask_path(upb_json_parser *p) {
 
   /* Start a new parser frame: parser frames correspond one-to-one with
    * handler frames, and string events occur in a sub-frame. */
-  inner = p->top + 1;
+  inner = start_jsonparser_frame(p);
   sel = getsel_for_handlertype(p, UPB_HANDLER_STARTSTR);
   upb_sink_startstr(p->top->sink, sel, 0, &inner->sink);
   inner->m = p->top->m;
   inner->f = p->top->f;
-  inner->name_table = NULL;
-  inner->is_map = false;
-  inner->is_mapentry = false;
-  inner->is_any = false;
-  inner->any_frame = NULL;
-  inner->is_unknown_field = false;
   p->top = inner;
 
   multipart_startaccum(p);
@@ -1829,17 +1842,12 @@ static bool handle_mapentry(upb_json_parser *p) {
   mapfield = p->top->mapfield;
   mapentrymsg = upb_fielddef_msgsubdef(mapfield);
 
-  inner = p->top + 1;
+  inner = start_jsonparser_frame(p);
   p->top->f = mapfield;
   sel = getsel_for_handlertype(p, UPB_HANDLER_STARTSUBMSG);
   upb_sink_startsubmsg(p->top->sink, sel, &inner->sink);
   inner->m = mapentrymsg;
-  inner->name_table = NULL;
   inner->mapfield = mapfield;
-  inner->is_map = false;
-  inner->is_any = false;
-  inner->any_frame = NULL;
-  inner->is_unknown_field = false;
 
   /* Don't set this to true *yet* -- we reuse parsing handlers below to push
    * the key field value to the sink, and these handlers will pop the frame
@@ -1954,15 +1962,7 @@ static bool start_subobject(upb_json_parser *p) {
     upb_jsonparser_frame *inner;
     if (!check_stack(p)) return false;
 
-    inner = p->top + 1;
-    inner->m = NULL;
-    inner->f = NULL;
-    inner->is_map = false;
-    inner->is_mapentry = false;
-    inner->is_any = false;
-    inner->any_frame = NULL;
-    inner->is_unknown_field = false;
-    p->top = inner;
+    p->top = start_jsonparser_frame(p);
     return true;
   }
 
@@ -1974,18 +1974,12 @@ static bool start_subobject(upb_json_parser *p) {
      * context. */
     if (!check_stack(p)) return false;
 
-    inner = p->top + 1;
+    inner = start_jsonparser_frame(p);
     sel = getsel_for_handlertype(p, UPB_HANDLER_STARTSEQ);
     upb_sink_startseq(p->top->sink, sel, &inner->sink);
     inner->m = upb_fielddef_msgsubdef(p->top->f);
-    inner->name_table = NULL;
     inner->mapfield = p->top->f;
-    inner->f = NULL;
     inner->is_map = true;
-    inner->is_mapentry = false;
-    inner->is_any = false;
-    inner->any_frame = NULL;
-    inner->is_unknown_field = false;
     p->top = inner;
 
     return true;
@@ -1997,16 +1991,11 @@ static bool start_subobject(upb_json_parser *p) {
      * context. */
     if (!check_stack(p)) return false;
 
-    inner = p->top + 1;
-
+    inner = start_jsonparser_frame(p);
     sel = getsel_for_handlertype(p, UPB_HANDLER_STARTSUBMSG);
     upb_sink_startsubmsg(p->top->sink, sel, &inner->sink);
     inner->m = upb_fielddef_msgsubdef(p->top->f);
     set_name_table(p, inner);
-    inner->f = NULL;
-    inner->is_map = false;
-    inner->is_mapentry = false;
-    inner->is_unknown_field = false;
     p->top = inner;
 
     if (is_wellknown_msg(p, UPB_WELLKNOWN_ANY)) {
@@ -2103,10 +2092,14 @@ static bool start_array(upb_json_parser *p) {
     } else {
       return false;
     }
-  } else if (is_wellknown_field(p, UPB_WELLKNOWN_LISTVALUE)) {
+  } else if (is_wellknown_field(p, UPB_WELLKNOWN_LISTVALUE) &&
+             (!upb_fielddef_isseq(p->top->f) ||
+              p->top->is_repeated)) {
     if (!start_subobject(p)) return false;
     start_listvalue_object(p);
-  } else if (is_wellknown_field(p, UPB_WELLKNOWN_VALUE)) {
+  } else if (is_wellknown_field(p, UPB_WELLKNOWN_VALUE) &&
+             (!upb_fielddef_isseq(p->top->f) ||
+              p->top->is_repeated)) {
     if (!start_subobject(p)) return false;
     start_value_object(p, VALUE_LISTVALUE);
     if (!start_subobject(p)) return false;
@@ -2114,14 +2107,7 @@ static bool start_array(upb_json_parser *p) {
   }
 
   if (p->top->is_unknown_field) {
-    inner = p->top + 1;
-    inner->m = NULL;
-    inner->name_table = NULL;
-    inner->f = NULL;
-    inner->is_map = false;
-    inner->is_mapentry = false;
-    inner->is_any = false;
-    inner->any_frame = NULL;
+    inner = start_jsonparser_frame(p);
     inner->is_unknown_field = true;
     p->top = inner;
 
@@ -2137,17 +2123,12 @@ static bool start_array(upb_json_parser *p) {
 
   if (!check_stack(p)) return false;
 
-  inner = p->top + 1;
+  inner = start_jsonparser_frame(p);
   sel = getsel_for_handlertype(p, UPB_HANDLER_STARTSEQ);
   upb_sink_startseq(p->top->sink, sel, &inner->sink);
   inner->m = p->top->m;
-  inner->name_table = NULL;
   inner->f = p->top->f;
-  inner->is_map = false;
-  inner->is_mapentry = false;
-  inner->is_any = false;
-  inner->any_frame = NULL;
-  inner->is_unknown_field = false;
+  inner->is_repeated = true;
   p->top = inner;
 
   return true;
@@ -2513,11 +2494,11 @@ static bool does_fieldmask_end(upb_json_parser *p) {
  * final state once, when the closing '"' is seen. */
 
 
-#line 2695 "upb/json/parser.rl"
+#line 2676 "upb/json/parser.rl"
 
 
 
-#line 2521 "upb/json/parser.c"
+#line 2502 "upb/json/parser.c"
 static const char _json_actions[] = {
 	0, 1, 0, 1, 1, 1, 3, 1, 
 	4, 1, 6, 1, 7, 1, 8, 1, 
@@ -2769,7 +2750,7 @@ static const int json_en_value_machine = 78;
 static const int json_en_main = 1;
 
 
-#line 2698 "upb/json/parser.rl"
+#line 2679 "upb/json/parser.rl"
 
 size_t parse(void *closure, const void *hd, const char *buf, size_t size,
              const upb_bufhandle *handle) {
@@ -2792,7 +2773,7 @@ size_t parse(void *closure, const void *hd, const char *buf, size_t size,
   capture_resume(parser, buf);
 
   
-#line 2796 "upb/json/parser.c"
+#line 2777 "upb/json/parser.c"
 	{
 	int _klen;
 	unsigned int _trans;
@@ -2867,103 +2848,103 @@ _match:
 		switch ( *_acts++ )
 		{
 	case 1:
-#line 2526 "upb/json/parser.rl"
+#line 2507 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; goto _again;} }
 	break;
 	case 2:
-#line 2528 "upb/json/parser.rl"
+#line 2509 "upb/json/parser.rl"
 	{ p--; {stack[top++] = cs; cs = 23;goto _again;} }
 	break;
 	case 3:
-#line 2532 "upb/json/parser.rl"
+#line 2513 "upb/json/parser.rl"
 	{ start_text(parser, p); }
 	break;
 	case 4:
-#line 2533 "upb/json/parser.rl"
+#line 2514 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_text(parser, p)); }
 	break;
 	case 5:
-#line 2539 "upb/json/parser.rl"
+#line 2520 "upb/json/parser.rl"
 	{ start_hex(parser); }
 	break;
 	case 6:
-#line 2540 "upb/json/parser.rl"
+#line 2521 "upb/json/parser.rl"
 	{ hexdigit(parser, p); }
 	break;
 	case 7:
-#line 2541 "upb/json/parser.rl"
+#line 2522 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_hex(parser)); }
 	break;
 	case 8:
-#line 2547 "upb/json/parser.rl"
+#line 2528 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(escape(parser, p)); }
 	break;
 	case 9:
-#line 2553 "upb/json/parser.rl"
+#line 2534 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; goto _again;} }
 	break;
 	case 10:
-#line 2565 "upb/json/parser.rl"
+#line 2546 "upb/json/parser.rl"
 	{ start_duration_base(parser, p); }
 	break;
 	case 11:
-#line 2566 "upb/json/parser.rl"
+#line 2547 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_duration_base(parser, p)); }
 	break;
 	case 12:
-#line 2568 "upb/json/parser.rl"
+#line 2549 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; goto _again;} }
 	break;
 	case 13:
-#line 2573 "upb/json/parser.rl"
+#line 2554 "upb/json/parser.rl"
 	{ start_timestamp_base(parser, p); }
 	break;
 	case 14:
-#line 2574 "upb/json/parser.rl"
+#line 2555 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_timestamp_base(parser, p)); }
 	break;
 	case 15:
-#line 2576 "upb/json/parser.rl"
+#line 2557 "upb/json/parser.rl"
 	{ start_timestamp_fraction(parser, p); }
 	break;
 	case 16:
-#line 2577 "upb/json/parser.rl"
+#line 2558 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_timestamp_fraction(parser, p)); }
 	break;
 	case 17:
-#line 2579 "upb/json/parser.rl"
+#line 2560 "upb/json/parser.rl"
 	{ start_timestamp_zone(parser, p); }
 	break;
 	case 18:
-#line 2580 "upb/json/parser.rl"
+#line 2561 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_timestamp_zone(parser, p)); }
 	break;
 	case 19:
-#line 2582 "upb/json/parser.rl"
+#line 2563 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; goto _again;} }
 	break;
 	case 20:
-#line 2587 "upb/json/parser.rl"
+#line 2568 "upb/json/parser.rl"
 	{ start_fieldmask_path_text(parser, p); }
 	break;
 	case 21:
-#line 2588 "upb/json/parser.rl"
+#line 2569 "upb/json/parser.rl"
 	{ end_fieldmask_path_text(parser, p); }
 	break;
 	case 22:
-#line 2593 "upb/json/parser.rl"
+#line 2574 "upb/json/parser.rl"
 	{ start_fieldmask_path(parser); }
 	break;
 	case 23:
-#line 2594 "upb/json/parser.rl"
+#line 2575 "upb/json/parser.rl"
 	{ end_fieldmask_path(parser); }
 	break;
 	case 24:
-#line 2600 "upb/json/parser.rl"
+#line 2581 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; goto _again;} }
 	break;
 	case 25:
-#line 2605 "upb/json/parser.rl"
+#line 2586 "upb/json/parser.rl"
 	{
         if (is_wellknown_msg(parser, UPB_WELLKNOWN_TIMESTAMP)) {
           {stack[top++] = cs; cs = 47;goto _again;}
@@ -2977,11 +2958,11 @@ _match:
       }
 	break;
 	case 26:
-#line 2618 "upb/json/parser.rl"
+#line 2599 "upb/json/parser.rl"
 	{ p--; {stack[top++] = cs; cs = 78;goto _again;} }
 	break;
 	case 27:
-#line 2623 "upb/json/parser.rl"
+#line 2604 "upb/json/parser.rl"
 	{
         if (is_wellknown_msg(parser, UPB_WELLKNOWN_ANY)) {
           start_any_member(parser, p);
@@ -2991,11 +2972,11 @@ _match:
       }
 	break;
 	case 28:
-#line 2630 "upb/json/parser.rl"
+#line 2611 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_membername(parser)); }
 	break;
 	case 29:
-#line 2633 "upb/json/parser.rl"
+#line 2614 "upb/json/parser.rl"
 	{
         if (is_wellknown_msg(parser, UPB_WELLKNOWN_ANY)) {
           end_any_member(parser, p);
@@ -3005,7 +2986,7 @@ _match:
       }
 	break;
 	case 30:
-#line 2644 "upb/json/parser.rl"
+#line 2625 "upb/json/parser.rl"
 	{
         if (is_wellknown_msg(parser, UPB_WELLKNOWN_ANY)) {
           start_any_object(parser, p);
@@ -3015,7 +2996,7 @@ _match:
       }
 	break;
 	case 31:
-#line 2653 "upb/json/parser.rl"
+#line 2634 "upb/json/parser.rl"
 	{
         if (is_wellknown_msg(parser, UPB_WELLKNOWN_ANY)) {
           CHECK_RETURN_TOP(end_any_object(parser, p));
@@ -3025,54 +3006,54 @@ _match:
       }
 	break;
 	case 32:
-#line 2665 "upb/json/parser.rl"
+#line 2646 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(start_array(parser)); }
 	break;
 	case 33:
-#line 2669 "upb/json/parser.rl"
+#line 2650 "upb/json/parser.rl"
 	{ end_array(parser); }
 	break;
 	case 34:
-#line 2674 "upb/json/parser.rl"
+#line 2655 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(start_number(parser, p)); }
 	break;
 	case 35:
-#line 2675 "upb/json/parser.rl"
+#line 2656 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_number(parser, p)); }
 	break;
 	case 36:
-#line 2677 "upb/json/parser.rl"
+#line 2658 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(start_stringval(parser)); }
 	break;
 	case 37:
-#line 2678 "upb/json/parser.rl"
+#line 2659 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_stringval(parser)); }
 	break;
 	case 38:
-#line 2680 "upb/json/parser.rl"
+#line 2661 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_bool(parser, true)); }
 	break;
 	case 39:
-#line 2682 "upb/json/parser.rl"
+#line 2663 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_bool(parser, false)); }
 	break;
 	case 40:
-#line 2684 "upb/json/parser.rl"
+#line 2665 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_null(parser)); }
 	break;
 	case 41:
-#line 2686 "upb/json/parser.rl"
+#line 2667 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(start_subobject_full(parser)); }
 	break;
 	case 42:
-#line 2687 "upb/json/parser.rl"
+#line 2668 "upb/json/parser.rl"
 	{ end_subobject_full(parser); }
 	break;
 	case 43:
-#line 2692 "upb/json/parser.rl"
+#line 2673 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; goto _again;} }
 	break;
-#line 3076 "upb/json/parser.c"
+#line 3057 "upb/json/parser.c"
 		}
 	}
 
@@ -3089,32 +3070,32 @@ _again:
 	while ( __nacts-- > 0 ) {
 		switch ( *__acts++ ) {
 	case 0:
-#line 2524 "upb/json/parser.rl"
+#line 2505 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; 	if ( p == pe )
 		goto _test_eof;
 goto _again;} }
 	break;
 	case 35:
-#line 2675 "upb/json/parser.rl"
+#line 2656 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_number(parser, p)); }
 	break;
 	case 38:
-#line 2680 "upb/json/parser.rl"
+#line 2661 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_bool(parser, true)); }
 	break;
 	case 39:
-#line 2682 "upb/json/parser.rl"
+#line 2663 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_bool(parser, false)); }
 	break;
 	case 40:
-#line 2684 "upb/json/parser.rl"
+#line 2665 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_null(parser)); }
 	break;
 	case 42:
-#line 2687 "upb/json/parser.rl"
+#line 2668 "upb/json/parser.rl"
 	{ end_subobject_full(parser); }
 	break;
-#line 3118 "upb/json/parser.c"
+#line 3099 "upb/json/parser.c"
 		}
 	}
 	}
@@ -3122,7 +3103,7 @@ goto _again;} }
 	_out: {}
 	}
 
-#line 2720 "upb/json/parser.rl"
+#line 2701 "upb/json/parser.rl"
 
   if (p != pe) {
     upb_status_seterrf(parser->status, "Parse error at '%.*s'\n", pe - p, p);
@@ -3161,22 +3142,17 @@ static void json_parser_reset(upb_json_parser *p) {
   int top;
 
   p->top = p->stack;
-  p->top->f = NULL;
-  p->top->is_map = false;
-  p->top->is_mapentry = false;
-  p->top->is_any = false;
-  p->top->any_frame = NULL;
-  p->top->is_unknown_field = false;
+  init_frame(p->top);
 
   /* Emit Ragel initialization of the parser. */
   
-#line 3174 "upb/json/parser.c"
+#line 3150 "upb/json/parser.c"
 	{
 	cs = json_start;
 	top = 0;
 	}
 
-#line 2767 "upb/json/parser.rl"
+#line 2743 "upb/json/parser.rl"
   p->current_state = cs;
   p->parser_top = top;
   accumulate_clear(p);
diff --git a/upb/json/parser.rl b/upb/json/parser.rl
index 3444257cf1..23e61b7b4b 100644
--- a/upb/json/parser.rl
+++ b/upb/json/parser.rl
@@ -184,6 +184,11 @@ typedef struct {
   /* The table mapping json name to fielddef for this message. */
   const upb_strtable *name_table;
 
+  /* We are in a repeated-field context. We need this flag to decide whether to
+   * handle the array as a normal repeated field or a
+   * google.protobuf.ListValue/google.protobuf.Value. */
+  bool is_repeated;
+
   /* We are in a repeated-field context, ready to emit mapentries as
    * submessages. This flag alters the start-of-object (open-brace) behavior to
    * begin a sequence of mapentry messages rather than a single submessage. */
@@ -214,6 +219,19 @@ typedef struct {
   bool is_unknown_field;
 } upb_jsonparser_frame;
 
+static void init_frame(upb_jsonparser_frame* frame) {
+  frame->m = NULL;
+  frame->f = NULL;
+  frame->name_table = NULL;
+  frame->is_repeated = false;
+  frame->is_map = false;
+  frame->is_mapentry = false;
+  frame->mapfield = NULL;
+  frame->is_any = false;
+  frame->any_frame = NULL;
+  frame->is_unknown_field = false;
+}
+
 struct upb_json_parser {
   upb_arena *arena;
   const upb_json_parsermethod *method;
@@ -261,6 +279,13 @@ struct upb_json_parser {
   struct tm tm;
 };
 
+static upb_jsonparser_frame* start_jsonparser_frame(upb_json_parser *p) {
+  upb_jsonparser_frame *inner;
+  inner = p->top + 1;
+  init_frame(inner);
+  return inner;
+}
+
 struct upb_json_codecache {
   upb_arena *arena;
   upb_inttable methods;   /* upb_msgdef* -> upb_json_parsermethod* */
@@ -1219,17 +1244,11 @@ static bool start_stringval(upb_json_parser *p) {
 
     /* Start a new parser frame: parser frames correspond one-to-one with
      * handler frames, and string events occur in a sub-frame. */
-    inner = p->top + 1;
+    inner = start_jsonparser_frame(p);
     sel = getsel_for_handlertype(p, UPB_HANDLER_STARTSTR);
     upb_sink_startstr(p->top->sink, sel, 0, &inner->sink);
     inner->m = p->top->m;
     inner->f = p->top->f;
-    inner->name_table = NULL;
-    inner->is_map = false;
-    inner->is_mapentry = false;
-    inner->is_any = false;
-    inner->any_frame = NULL;
-    inner->is_unknown_field = false;
     p->top = inner;
 
     if (upb_fielddef_type(p->top->f) == UPB_TYPE_STRING) {
@@ -1684,17 +1703,11 @@ static bool start_fieldmask_path(upb_json_parser *p) {
 
   /* Start a new parser frame: parser frames correspond one-to-one with
    * handler frames, and string events occur in a sub-frame. */
-  inner = p->top + 1;
+  inner = start_jsonparser_frame(p);
   sel = getsel_for_handlertype(p, UPB_HANDLER_STARTSTR);
   upb_sink_startstr(p->top->sink, sel, 0, &inner->sink);
   inner->m = p->top->m;
   inner->f = p->top->f;
-  inner->name_table = NULL;
-  inner->is_map = false;
-  inner->is_mapentry = false;
-  inner->is_any = false;
-  inner->any_frame = NULL;
-  inner->is_unknown_field = false;
   p->top = inner;
 
   multipart_startaccum(p);
@@ -1827,17 +1840,12 @@ static bool handle_mapentry(upb_json_parser *p) {
   mapfield = p->top->mapfield;
   mapentrymsg = upb_fielddef_msgsubdef(mapfield);
 
-  inner = p->top + 1;
+  inner = start_jsonparser_frame(p);
   p->top->f = mapfield;
   sel = getsel_for_handlertype(p, UPB_HANDLER_STARTSUBMSG);
   upb_sink_startsubmsg(p->top->sink, sel, &inner->sink);
   inner->m = mapentrymsg;
-  inner->name_table = NULL;
   inner->mapfield = mapfield;
-  inner->is_map = false;
-  inner->is_any = false;
-  inner->any_frame = NULL;
-  inner->is_unknown_field = false;
 
   /* Don't set this to true *yet* -- we reuse parsing handlers below to push
    * the key field value to the sink, and these handlers will pop the frame
@@ -1952,15 +1960,7 @@ static bool start_subobject(upb_json_parser *p) {
     upb_jsonparser_frame *inner;
     if (!check_stack(p)) return false;
 
-    inner = p->top + 1;
-    inner->m = NULL;
-    inner->f = NULL;
-    inner->is_map = false;
-    inner->is_mapentry = false;
-    inner->is_any = false;
-    inner->any_frame = NULL;
-    inner->is_unknown_field = false;
-    p->top = inner;
+    p->top = start_jsonparser_frame(p);
     return true;
   }
 
@@ -1972,18 +1972,12 @@ static bool start_subobject(upb_json_parser *p) {
      * context. */
     if (!check_stack(p)) return false;
 
-    inner = p->top + 1;
+    inner = start_jsonparser_frame(p);
     sel = getsel_for_handlertype(p, UPB_HANDLER_STARTSEQ);
     upb_sink_startseq(p->top->sink, sel, &inner->sink);
     inner->m = upb_fielddef_msgsubdef(p->top->f);
-    inner->name_table = NULL;
     inner->mapfield = p->top->f;
-    inner->f = NULL;
     inner->is_map = true;
-    inner->is_mapentry = false;
-    inner->is_any = false;
-    inner->any_frame = NULL;
-    inner->is_unknown_field = false;
     p->top = inner;
 
     return true;
@@ -1995,16 +1989,11 @@ static bool start_subobject(upb_json_parser *p) {
      * context. */
     if (!check_stack(p)) return false;
 
-    inner = p->top + 1;
-
+    inner = start_jsonparser_frame(p);
     sel = getsel_for_handlertype(p, UPB_HANDLER_STARTSUBMSG);
     upb_sink_startsubmsg(p->top->sink, sel, &inner->sink);
     inner->m = upb_fielddef_msgsubdef(p->top->f);
     set_name_table(p, inner);
-    inner->f = NULL;
-    inner->is_map = false;
-    inner->is_mapentry = false;
-    inner->is_unknown_field = false;
     p->top = inner;
 
     if (is_wellknown_msg(p, UPB_WELLKNOWN_ANY)) {
@@ -2101,10 +2090,14 @@ static bool start_array(upb_json_parser *p) {
     } else {
       return false;
     }
-  } else if (is_wellknown_field(p, UPB_WELLKNOWN_LISTVALUE)) {
+  } else if (is_wellknown_field(p, UPB_WELLKNOWN_LISTVALUE) &&
+             (!upb_fielddef_isseq(p->top->f) ||
+              p->top->is_repeated)) {
     if (!start_subobject(p)) return false;
     start_listvalue_object(p);
-  } else if (is_wellknown_field(p, UPB_WELLKNOWN_VALUE)) {
+  } else if (is_wellknown_field(p, UPB_WELLKNOWN_VALUE) &&
+             (!upb_fielddef_isseq(p->top->f) ||
+              p->top->is_repeated)) {
     if (!start_subobject(p)) return false;
     start_value_object(p, VALUE_LISTVALUE);
     if (!start_subobject(p)) return false;
@@ -2112,14 +2105,7 @@ static bool start_array(upb_json_parser *p) {
   }
 
   if (p->top->is_unknown_field) {
-    inner = p->top + 1;
-    inner->m = NULL;
-    inner->name_table = NULL;
-    inner->f = NULL;
-    inner->is_map = false;
-    inner->is_mapentry = false;
-    inner->is_any = false;
-    inner->any_frame = NULL;
+    inner = start_jsonparser_frame(p);
     inner->is_unknown_field = true;
     p->top = inner;
 
@@ -2135,17 +2121,12 @@ static bool start_array(upb_json_parser *p) {
 
   if (!check_stack(p)) return false;
 
-  inner = p->top + 1;
+  inner = start_jsonparser_frame(p);
   sel = getsel_for_handlertype(p, UPB_HANDLER_STARTSEQ);
   upb_sink_startseq(p->top->sink, sel, &inner->sink);
   inner->m = p->top->m;
-  inner->name_table = NULL;
   inner->f = p->top->f;
-  inner->is_map = false;
-  inner->is_mapentry = false;
-  inner->is_any = false;
-  inner->any_frame = NULL;
-  inner->is_unknown_field = false;
+  inner->is_repeated = true;
   p->top = inner;
 
   return true;
@@ -2755,12 +2736,7 @@ static void json_parser_reset(upb_json_parser *p) {
   int top;
 
   p->top = p->stack;
-  p->top->f = NULL;
-  p->top->is_map = false;
-  p->top->is_mapentry = false;
-  p->top->is_any = false;
-  p->top->any_frame = NULL;
-  p->top->is_unknown_field = false;
+  init_frame(p->top);
 
   /* Emit Ragel initialization of the parser. */
   %% write init;