diff --git a/modules/docs/src/Volo.Docs.Domain/Volo/Docs/Documents/Document.cs b/modules/docs/src/Volo.Docs.Domain/Volo/Docs/Documents/Document.cs
index ee8710bff3..c2ec85f33b 100644
--- a/modules/docs/src/Volo.Docs.Domain/Volo/Docs/Documents/Document.cs
+++ b/modules/docs/src/Volo.Docs.Domain/Volo/Docs/Documents/Document.cs
@@ -32,9 +32,9 @@ namespace Volo.Docs.Documents
         public virtual string LocalDirectory { get; set; }
 
         public virtual DateTime CreationTime { get; set; }
-        
+
         public virtual DateTime LastUpdatedTime { get; set; }
-        
+
         public virtual DateTime? LastSignificantUpdateTime { get; set; }
 
         public virtual DateTime LastCachedTime { get; set; }
@@ -44,7 +44,6 @@ namespace Volo.Docs.Documents
         protected Document()
         {
             Contributors = new List<DocumentContributor>();
-            ExtraProperties = new Dictionary<string, object>();
         }
 
         public Document(
@@ -65,8 +64,8 @@ namespace Volo.Docs.Documents
             DateTime lastCachedTime,
             DateTime? lastSignificantUpdateTime = null
         )
+            : base(id)
         {
-            Id = id;
             ProjectId = projectId;
 
             Name = Check.NotNullOrWhiteSpace(name, nameof(name));
@@ -86,7 +85,6 @@ namespace Volo.Docs.Documents
             LastSignificantUpdateTime = lastSignificantUpdateTime;
 
             Contributors = new List<DocumentContributor>();
-            ExtraProperties = new Dictionary<string, object>();
         }
 
         public virtual void AddContributor(string username, string userProfileUrl, string avatarUrl)
@@ -111,4 +109,4 @@ namespace Volo.Docs.Documents
                 r.Username == username && r.UserProfileUrl == userProfileUrl && r.AvatarUrl == avatarUrl);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/modules/docs/src/Volo.Docs.Domain/Volo/Docs/Projects/Project.cs b/modules/docs/src/Volo.Docs.Domain/Volo/Docs/Projects/Project.cs
index 8bc36a2106..720cf494d6 100644
--- a/modules/docs/src/Volo.Docs.Domain/Volo/Docs/Projects/Project.cs
+++ b/modules/docs/src/Volo.Docs.Domain/Volo/Docs/Projects/Project.cs
@@ -2,7 +2,6 @@ using System;
 using System.Collections.Generic;
 using JetBrains.Annotations;
 using Volo.Abp;
-using Volo.Abp.Data;
 using Volo.Abp.Domain.Entities;
 
 namespace Volo.Docs.Projects
@@ -52,21 +51,19 @@ namespace Volo.Docs.Projects
 
         protected Project()
         {
-            ExtraProperties = new Dictionary<string, object>();
         }
 
         public Project(
-            Guid id, 
-            [NotNull] string name, 
-            [NotNull] string shortName, 
+            Guid id,
+            [NotNull] string name,
+            [NotNull] string shortName,
             [NotNull] string documentStoreType,
             [NotNull] string format,
-            [NotNull] string defaultDocumentName = "Index", 
-            [NotNull] string navigationDocumentName = "docs-nav.json", 
+            [NotNull] string defaultDocumentName = "Index",
+            [NotNull] string navigationDocumentName = "docs-nav.json",
             [NotNull] string parametersDocumentName = "docs-params.json")
+            : base(id)
         {
-            Id = id;
-
             Name = Check.NotNullOrWhiteSpace(name, nameof(name));
             ShortName = Check.NotNullOrWhiteSpace(shortName, nameof(shortName));
             DocumentStoreType = Check.NotNullOrWhiteSpace(documentStoreType, nameof(documentStoreType));
@@ -75,8 +72,6 @@ namespace Volo.Docs.Projects
             NavigationDocumentName = Check.NotNullOrWhiteSpace(navigationDocumentName, nameof(navigationDocumentName));
             ParametersDocumentName = Check.NotNullOrWhiteSpace(parametersDocumentName, nameof(parametersDocumentName));
 
-            ExtraProperties = new Dictionary<string, object>();
-
             NormalizeShortName();
         }
 
@@ -110,4 +105,4 @@ namespace Volo.Docs.Projects
             ShortName = ShortName.ToLower();
         }
     }
-}
\ No newline at end of file
+}