diff --git a/php/ext/google/protobuf/php-upb.c b/php/ext/google/protobuf/php-upb.c
index fb226ca3c7a0..e02c084a12bb 100644
--- a/php/ext/google/protobuf/php-upb.c
+++ b/php/ext/google/protobuf/php-upb.c
@@ -3100,12 +3100,17 @@ typedef struct {
   const upb_FieldDef* debug_field;
 } jsondec;
 
+typedef struct {
+  upb_MessageValue value;
+  bool ignore;
+} upb_JsonMessageValue;
+
 enum { JD_OBJECT, JD_ARRAY, JD_STRING, JD_NUMBER, JD_TRUE, JD_FALSE, JD_NULL };
 
 /* Forward declarations of mutually-recursive functions. */
 static void jsondec_wellknown(jsondec* d, upb_Message* msg,
                               const upb_MessageDef* m);
-static upb_MessageValue jsondec_value(jsondec* d, const upb_FieldDef* f);
+static upb_JsonMessageValue jsondec_value(jsondec* d, const upb_FieldDef* f);
 static void jsondec_wellknownvalue(jsondec* d, upb_Message* msg,
                                    const upb_MessageDef* m);
 static void jsondec_object(jsondec* d, upb_Message* msg,
@@ -3836,19 +3841,19 @@ static upb_MessageValue jsondec_strfield(jsondec* d, const upb_FieldDef* f) {
   return val;
 }
 
-static upb_MessageValue jsondec_enum(jsondec* d, const upb_FieldDef* f) {
+static upb_JsonMessageValue jsondec_enum(jsondec* d, const upb_FieldDef* f) {
   switch (jsondec_peek(d)) {
     case JD_STRING: {
       upb_StringView str = jsondec_string(d);
       const upb_EnumDef* e = upb_FieldDef_EnumSubDef(f);
       const upb_EnumValueDef* ev =
           upb_EnumDef_FindValueByNameWithSize(e, str.data, str.size);
-      upb_MessageValue val;
+      upb_JsonMessageValue val = {.ignore = false};
       if (ev) {
-        val.int32_val = upb_EnumValueDef_Number(ev);
+        val.value.int32_val = upb_EnumValueDef_Number(ev);
       } else {
         if (d->options & upb_JsonDecode_IgnoreUnknown) {
-          val.int32_val = 0;
+          val.ignore = true;
         } else {
           jsondec_errf(d, "Unknown enumerator: '" UPB_STRINGVIEW_FORMAT "'",
                        UPB_STRINGVIEW_ARGS(str));
@@ -3858,15 +3863,16 @@ static upb_MessageValue jsondec_enum(jsondec* d, const upb_FieldDef* f) {
     }
     case JD_NULL: {
       if (jsondec_isnullvalue(f)) {
-        upb_MessageValue val;
+        upb_JsonMessageValue val = {.ignore = false};
         jsondec_null(d);
-        val.int32_val = 0;
+        val.value.int32_val = 0;
         return val;
       }
     }
       /* Fallthrough. */
     default:
-      return jsondec_int(d, f);
+      return (upb_JsonMessageValue){.value = jsondec_int(d, f),
+                                    .ignore = false};
   }
 }
 
@@ -3909,8 +3915,10 @@ static void jsondec_array(jsondec* d, upb_Message* msg, const upb_FieldDef* f) {
 
   jsondec_arrstart(d);
   while (jsondec_arrnext(d)) {
-    upb_MessageValue elem = jsondec_value(d, f);
-    upb_Array_Append(arr, elem, d->arena);
+    upb_JsonMessageValue elem = jsondec_value(d, f);
+    if (!elem.ignore) {
+      upb_Array_Append(arr, elem.value, d->arena);
+    }
   }
   jsondec_arrend(d);
 }
@@ -3923,11 +3931,14 @@ static void jsondec_map(jsondec* d, upb_Message* msg, const upb_FieldDef* f) {
 
   jsondec_objstart(d);
   while (jsondec_objnext(d)) {
-    upb_MessageValue key, val;
+    upb_JsonMessageValue key, val;
     key = jsondec_value(d, key_f);
+    UPB_ASSUME(!key.ignore);  // Map key cannot be enum.
     jsondec_entrysep(d);
     val = jsondec_value(d, val_f);
-    upb_Map_Set(map, key, val, d->arena);
+    if (!val.ignore) {
+      upb_Map_Set(map, key.value, val.value, d->arena);
+    }
   }
   jsondec_objend(d);
 }
@@ -4008,8 +4019,10 @@ static void jsondec_field(jsondec* d, upb_Message* msg,
     const upb_MessageDef* subm = upb_FieldDef_MessageSubDef(f);
     jsondec_tomsg(d, submsg, subm);
   } else {
-    upb_MessageValue val = jsondec_value(d, f);
-    upb_Message_SetFieldByDef(msg, f, val, d->arena);
+    upb_JsonMessageValue val = jsondec_value(d, f);
+    if (!val.ignore) {
+      upb_Message_SetFieldByDef(msg, f, val.value, d->arena);
+    }
   }
 
   d->debug_field = preserved;
@@ -4024,7 +4037,7 @@ static void jsondec_object(jsondec* d, upb_Message* msg,
   jsondec_objend(d);
 }
 
-static upb_MessageValue jsondec_value(jsondec* d, const upb_FieldDef* f) {
+static upb_MessageValue jsondec_nonenum(jsondec* d, const upb_FieldDef* f) {
   switch (upb_FieldDef_CType(f)) {
     case kUpb_CType_Bool:
       return jsondec_bool(d, f);
@@ -4040,15 +4053,23 @@ static upb_MessageValue jsondec_value(jsondec* d, const upb_FieldDef* f) {
     case kUpb_CType_String:
     case kUpb_CType_Bytes:
       return jsondec_strfield(d, f);
-    case kUpb_CType_Enum:
-      return jsondec_enum(d, f);
     case kUpb_CType_Message:
       return jsondec_msg(d, f);
+    case kUpb_CType_Enum:
     default:
       UPB_UNREACHABLE();
   }
 }
 
+static upb_JsonMessageValue jsondec_value(jsondec* d, const upb_FieldDef* f) {
+  if (upb_FieldDef_CType(f) == kUpb_CType_Enum) {
+    return jsondec_enum(d, f);
+  } else {
+    return (upb_JsonMessageValue){.value = jsondec_nonenum(d, f),
+                                  .ignore = false};
+  }
+}
+
 /* Well-known types ***********************************************************/
 
 static int jsondec_tsdigits(jsondec* d, const char** ptr, size_t digits,
@@ -4473,8 +4494,9 @@ static void jsondec_any(jsondec* d, upb_Message* msg, const upb_MessageDef* m) {
 static void jsondec_wrapper(jsondec* d, upb_Message* msg,
                             const upb_MessageDef* m) {
   const upb_FieldDef* value_f = upb_MessageDef_FindFieldByNumber(m, 1);
-  upb_MessageValue val = jsondec_value(d, value_f);
-  upb_Message_SetFieldByDef(msg, value_f, val, d->arena);
+  upb_JsonMessageValue val = jsondec_value(d, value_f);
+  UPB_ASSUME(val.ignore == false);  // Wrapper cannot be an enum.
+  upb_Message_SetFieldByDef(msg, value_f, val.value, d->arena);
 }
 
 static void jsondec_wellknown(jsondec* d, upb_Message* msg,
diff --git a/ruby/ext/google/protobuf_c/ruby-upb.c b/ruby/ext/google/protobuf_c/ruby-upb.c
index eac3e83cee60..d2ea1895bc53 100644
--- a/ruby/ext/google/protobuf_c/ruby-upb.c
+++ b/ruby/ext/google/protobuf_c/ruby-upb.c
@@ -2616,12 +2616,17 @@ typedef struct {
   const upb_FieldDef* debug_field;
 } jsondec;
 
+typedef struct {
+  upb_MessageValue value;
+  bool ignore;
+} upb_JsonMessageValue;
+
 enum { JD_OBJECT, JD_ARRAY, JD_STRING, JD_NUMBER, JD_TRUE, JD_FALSE, JD_NULL };
 
 /* Forward declarations of mutually-recursive functions. */
 static void jsondec_wellknown(jsondec* d, upb_Message* msg,
                               const upb_MessageDef* m);
-static upb_MessageValue jsondec_value(jsondec* d, const upb_FieldDef* f);
+static upb_JsonMessageValue jsondec_value(jsondec* d, const upb_FieldDef* f);
 static void jsondec_wellknownvalue(jsondec* d, upb_Message* msg,
                                    const upb_MessageDef* m);
 static void jsondec_object(jsondec* d, upb_Message* msg,
@@ -3352,19 +3357,19 @@ static upb_MessageValue jsondec_strfield(jsondec* d, const upb_FieldDef* f) {
   return val;
 }
 
-static upb_MessageValue jsondec_enum(jsondec* d, const upb_FieldDef* f) {
+static upb_JsonMessageValue jsondec_enum(jsondec* d, const upb_FieldDef* f) {
   switch (jsondec_peek(d)) {
     case JD_STRING: {
       upb_StringView str = jsondec_string(d);
       const upb_EnumDef* e = upb_FieldDef_EnumSubDef(f);
       const upb_EnumValueDef* ev =
           upb_EnumDef_FindValueByNameWithSize(e, str.data, str.size);
-      upb_MessageValue val;
+      upb_JsonMessageValue val = {.ignore = false};
       if (ev) {
-        val.int32_val = upb_EnumValueDef_Number(ev);
+        val.value.int32_val = upb_EnumValueDef_Number(ev);
       } else {
         if (d->options & upb_JsonDecode_IgnoreUnknown) {
-          val.int32_val = 0;
+          val.ignore = true;
         } else {
           jsondec_errf(d, "Unknown enumerator: '" UPB_STRINGVIEW_FORMAT "'",
                        UPB_STRINGVIEW_ARGS(str));
@@ -3374,15 +3379,16 @@ static upb_MessageValue jsondec_enum(jsondec* d, const upb_FieldDef* f) {
     }
     case JD_NULL: {
       if (jsondec_isnullvalue(f)) {
-        upb_MessageValue val;
+        upb_JsonMessageValue val = {.ignore = false};
         jsondec_null(d);
-        val.int32_val = 0;
+        val.value.int32_val = 0;
         return val;
       }
     }
       /* Fallthrough. */
     default:
-      return jsondec_int(d, f);
+      return (upb_JsonMessageValue){.value = jsondec_int(d, f),
+                                    .ignore = false};
   }
 }
 
@@ -3425,8 +3431,10 @@ static void jsondec_array(jsondec* d, upb_Message* msg, const upb_FieldDef* f) {
 
   jsondec_arrstart(d);
   while (jsondec_arrnext(d)) {
-    upb_MessageValue elem = jsondec_value(d, f);
-    upb_Array_Append(arr, elem, d->arena);
+    upb_JsonMessageValue elem = jsondec_value(d, f);
+    if (!elem.ignore) {
+      upb_Array_Append(arr, elem.value, d->arena);
+    }
   }
   jsondec_arrend(d);
 }
@@ -3439,11 +3447,14 @@ static void jsondec_map(jsondec* d, upb_Message* msg, const upb_FieldDef* f) {
 
   jsondec_objstart(d);
   while (jsondec_objnext(d)) {
-    upb_MessageValue key, val;
+    upb_JsonMessageValue key, val;
     key = jsondec_value(d, key_f);
+    UPB_ASSUME(!key.ignore);  // Map key cannot be enum.
     jsondec_entrysep(d);
     val = jsondec_value(d, val_f);
-    upb_Map_Set(map, key, val, d->arena);
+    if (!val.ignore) {
+      upb_Map_Set(map, key.value, val.value, d->arena);
+    }
   }
   jsondec_objend(d);
 }
@@ -3524,8 +3535,10 @@ static void jsondec_field(jsondec* d, upb_Message* msg,
     const upb_MessageDef* subm = upb_FieldDef_MessageSubDef(f);
     jsondec_tomsg(d, submsg, subm);
   } else {
-    upb_MessageValue val = jsondec_value(d, f);
-    upb_Message_SetFieldByDef(msg, f, val, d->arena);
+    upb_JsonMessageValue val = jsondec_value(d, f);
+    if (!val.ignore) {
+      upb_Message_SetFieldByDef(msg, f, val.value, d->arena);
+    }
   }
 
   d->debug_field = preserved;
@@ -3540,7 +3553,7 @@ static void jsondec_object(jsondec* d, upb_Message* msg,
   jsondec_objend(d);
 }
 
-static upb_MessageValue jsondec_value(jsondec* d, const upb_FieldDef* f) {
+static upb_MessageValue jsondec_nonenum(jsondec* d, const upb_FieldDef* f) {
   switch (upb_FieldDef_CType(f)) {
     case kUpb_CType_Bool:
       return jsondec_bool(d, f);
@@ -3556,15 +3569,23 @@ static upb_MessageValue jsondec_value(jsondec* d, const upb_FieldDef* f) {
     case kUpb_CType_String:
     case kUpb_CType_Bytes:
       return jsondec_strfield(d, f);
-    case kUpb_CType_Enum:
-      return jsondec_enum(d, f);
     case kUpb_CType_Message:
       return jsondec_msg(d, f);
+    case kUpb_CType_Enum:
     default:
       UPB_UNREACHABLE();
   }
 }
 
+static upb_JsonMessageValue jsondec_value(jsondec* d, const upb_FieldDef* f) {
+  if (upb_FieldDef_CType(f) == kUpb_CType_Enum) {
+    return jsondec_enum(d, f);
+  } else {
+    return (upb_JsonMessageValue){.value = jsondec_nonenum(d, f),
+                                  .ignore = false};
+  }
+}
+
 /* Well-known types ***********************************************************/
 
 static int jsondec_tsdigits(jsondec* d, const char** ptr, size_t digits,
@@ -3989,8 +4010,9 @@ static void jsondec_any(jsondec* d, upb_Message* msg, const upb_MessageDef* m) {
 static void jsondec_wrapper(jsondec* d, upb_Message* msg,
                             const upb_MessageDef* m) {
   const upb_FieldDef* value_f = upb_MessageDef_FindFieldByNumber(m, 1);
-  upb_MessageValue val = jsondec_value(d, value_f);
-  upb_Message_SetFieldByDef(msg, value_f, val, d->arena);
+  upb_JsonMessageValue val = jsondec_value(d, value_f);
+  UPB_ASSUME(val.ignore == false);  // Wrapper cannot be an enum.
+  upb_Message_SetFieldByDef(msg, value_f, val.value, d->arena);
 }
 
 static void jsondec_wellknown(jsondec* d, upb_Message* msg,