diff --git a/src/Umbraco.Core/Migrations/Upgrade/V_8_15_0/AddPropertyTypeGroupColumns.cs b/src/Umbraco.Core/Migrations/Upgrade/V_8_15_0/AddPropertyTypeGroupColumns.cs
index 0fa0905f36..395981faf5 100644
--- a/src/Umbraco.Core/Migrations/Upgrade/V_8_15_0/AddPropertyTypeGroupColumns.cs
+++ b/src/Umbraco.Core/Migrations/Upgrade/V_8_15_0/AddPropertyTypeGroupColumns.cs
@@ -12,9 +12,21 @@ namespace Umbraco.Core.Migrations.Upgrade.V_8_15_0
         public override void Migrate()
         {
             var columns = SqlSyntax.GetColumnsInSchema(Context.Database).ToList();
-          
-            AddColumnIfNotExists<PropertyTypeGroupDto>(columns, "parentId");
+
+            // Add new columns
+            AddColumnIfNotExists<PropertyTypeGroupDto>(columns, "parentKey");
+            AddColumnIfNotExists<PropertyTypeGroupDto>(columns, "level");
             AddColumnIfNotExists<PropertyTypeGroupDto>(columns, "icon");
+
+            // Create self-referencing foreign key
+            var constraints = SqlSyntax.GetConstraintsPerTable(Context.Database).ToList();
+            if (!constraints.Any(x => x.Item1.InvariantEquals(PropertyTypeGroupDto.TableName) && x.Item2.InvariantEquals("FK_cmsPropertyTypeGroup_parentKey")))
+            {
+                Create.ForeignKey("FK_cmsPropertyTypeGroup_parentKey")
+                    .FromTable(PropertyTypeGroupDto.TableName).ForeignColumn("parentKey")
+                    .ToTable(PropertyTypeGroupDto.TableName).PrimaryColumn("uniqueID")
+                    .Do();
+            }
         }
     }
 }
diff --git a/src/Umbraco.Core/Persistence/Dtos/PropertyTypeGroupDto.cs b/src/Umbraco.Core/Persistence/Dtos/PropertyTypeGroupDto.cs
index 14e5b75404..fe9ea1386a 100644
--- a/src/Umbraco.Core/Persistence/Dtos/PropertyTypeGroupDto.cs
+++ b/src/Umbraco.Core/Persistence/Dtos/PropertyTypeGroupDto.cs
@@ -17,9 +17,20 @@ namespace Umbraco.Core.Persistence.Dtos
         [PrimaryKeyColumn(IdentitySeed = 12)]
         public int Id { get; set; }
 
-        [Column("parentId")]
+        [Column("uniqueID")]
+        [NullSetting(NullSetting = NullSettings.NotNull)]
+        [Constraint(Default = SystemMethods.NewGuid)]
+        [Index(IndexTypes.UniqueNonClustered, Name = "IX_cmsPropertyTypeGroupUniqueID")]
+        public Guid UniqueId { get; set; }
+
+        [Column("parentKey")]
         [NullSetting(NullSetting = NullSettings.Null)]
-        public int? ParentId { get; set; }
+        [ForeignKey(typeof(PropertyTypeGroupDto), Column = "uniqueID", Name = "FK_" + TableName + "_parentKey")]
+        public Guid? ParentKey { get; set; }
+
+        [Column("level")]
+        [Constraint(Default = 1)] // TODO We default to 1 (property group) for backwards compatibility, but should use zero/no default at some point.
+        public short Level { get; set; }
 
         [Column("contenttypeNodeId")]
         [ForeignKey(typeof(ContentTypeDto), Column = "nodeId")]
@@ -38,11 +49,5 @@ namespace Umbraco.Core.Persistence.Dtos
         [ResultColumn]
         [Reference(ReferenceType.Many, ReferenceMemberName = "PropertyTypeGroupId")]
         public List<PropertyTypeDto> PropertyTypeDtos { get; set; }
-
-        [Column("uniqueID")]
-        [NullSetting(NullSetting = NullSettings.NotNull)]
-        [Constraint(Default = SystemMethods.NewGuid)]
-        [Index(IndexTypes.UniqueNonClustered, Name = "IX_cmsPropertyTypeGroupUniqueID")]
-        public Guid UniqueId { get; set; }
     }
 }