diff --git a/src/Umbraco.Core/Persistence/Dtos/ContentTypeDto.cs b/src/Umbraco.Core/Persistence/Dtos/ContentTypeDto.cs
index 68036dab4b..58ecd0cd39 100644
--- a/src/Umbraco.Core/Persistence/Dtos/ContentTypeDto.cs
+++ b/src/Umbraco.Core/Persistence/Dtos/ContentTypeDto.cs
@@ -9,6 +9,7 @@ namespace Umbraco.Core.Persistence.Dtos
     internal class ContentTypeDto
     {
         public const string TableName = Constants.DatabaseSchema.Tables.ContentType;
+        private string _alias;
 
         [Column("pk")]
         [PrimaryKeyColumn(IdentitySeed = 700)]
@@ -21,7 +22,7 @@ namespace Umbraco.Core.Persistence.Dtos
 
         [Column("alias")]
         [NullSetting(NullSetting = NullSettings.Null)]
-        public string Alias { get; set; }
+        public string Alias { get => _alias; set => _alias = value == null ? null : string.Intern(value); }
 
         [Column("icon")]
         [Index(IndexTypes.NonClustered)]
diff --git a/src/Umbraco.Core/Persistence/Dtos/PropertyTypeDto.cs b/src/Umbraco.Core/Persistence/Dtos/PropertyTypeDto.cs
index f22e4453f4..d5ce28d3b5 100644
--- a/src/Umbraco.Core/Persistence/Dtos/PropertyTypeDto.cs
+++ b/src/Umbraco.Core/Persistence/Dtos/PropertyTypeDto.cs
@@ -10,6 +10,8 @@ namespace Umbraco.Core.Persistence.Dtos
     [ExplicitColumns]
     internal class PropertyTypeDto
     {
+        private string _alias;
+
         [Column("id")]
         [PrimaryKeyColumn(IdentitySeed = 100)]
         public int Id { get; set; }
@@ -29,7 +31,7 @@ namespace Umbraco.Core.Persistence.Dtos
 
         [Index(IndexTypes.NonClustered, Name = "IX_cmsPropertyTypeAlias")]
         [Column("Alias")]
-        public string Alias { get; set; }
+        public string Alias { get => _alias; set => _alias = value == null ? null : string.Intern(value); }
 
         [Column("Name")]
         [NullSetting(NullSetting = NullSettings.Null)]