diff --git a/components/synedit/test/testsynsharededits.pas b/components/synedit/test/testsynsharededits.pas
index e0d5feec68..32729aee96 100644
--- a/components/synedit/test/testsynsharededits.pas
+++ b/components/synedit/test/testsynsharededits.pas
@@ -28,6 +28,7 @@ type
     function AddMark(EditIndex: Integer; Y, X: Integer) : TSynEditMark;
   published
     procedure TestMarks;
+    procedure TestBookMarks;
   end;
 
 implementation
@@ -122,8 +123,8 @@ begin
   // default setting is shared marklist
   FSynEdits[1].ShareOptions := [eosShareMarks];
   FSynEdits[1].ShareTextBufferFrom(FSynEdits[0]);
-
   SetLines(TestText1);
+
   CheckMarks('empty', 0, []);
   CheckMarks('empty', 1, []);
 
@@ -142,8 +143,8 @@ begin
   // setting is not shared marklist
   FSynEdits[1].ShareOptions := [];
   FSynEdits[1].ShareTextBufferFrom(FSynEdits[0]);
-
   SetLines(TestText1);
+
   CheckMarks('empty', 0, []);
   CheckMarks('empty', 1, []);
 
@@ -158,6 +159,146 @@ begin
 
 end;
 
+procedure TTestSynSharedEdits.TestBookMarks;
+  procedure CheckBMarks(Name: String; EditIndex: Integer; MarkList: Array of Integer);
+  var
+    m: TSynEditMark;
+    l: Array of Integer;
+    i, j: Integer;
+  begin
+    Name := BaseTestName + Name;
+    AssertEquals(Name + ' Edit: '+IntToStr(EditIndex)+' Count: ', length(MarkList) div 2, FSynEdits[EditIndex].Marks.Count);
+
+    SetLength(l, FSynEdits[EditIndex].Lines.Count);
+    for i := 0 to length(l)-1 do
+      l[i] := 0;
+
+    for i := 0 to (length(MarkList) div 2) - 1 do begin
+      l[MarkList[i*2+0]] := l[MarkList[i*2+0]] + 1;
+      m := FSynEdits[EditIndex].Marks[i];
+      AssertEquals(Name + ' Edit: '+IntToStr(EditIndex)+' Mark( '+IntToStr(i)+' ) Line: ',    MarkList[i*2+0], m.Line);
+      AssertEquals(Name + ' Edit: '+IntToStr(EditIndex)+' Mark( '+IntToStr(i)+' ) BookNum: ',  MarkList[i*2+1], m.BookmarkNumber);
+      AssertEquals(Name + ' Edit: '+IntToStr(EditIndex)+' Mark( '+IntToStr(i)+' ) IndexOf: ', i,               FSynEdits[EditIndex].Marks.IndexOf(m));
+    end;
+
+    for i := 0 to length(l)-1 do begin
+      j := 0;
+      if FSynEdits[EditIndex].Marks.Line[i] <> nil then
+        j := FSynEdits[EditIndex].Marks.Line[i].Count;
+      AssertEquals(Name + ' Edit: '+IntToStr(EditIndex)+' Count in line '+IntToStr(i)+': ',    l[i], j);
+    end;
+
+  end;
+
+var
+  e1, e2, e3: Integer;
+begin
+  {%region edits already shared }
+  ReCreateEdit(2);
+  // default setting is shared marklist
+  FSynEdits[1].ShareOptions := [eosShareMarks];
+  FSynEdits[1].ShareTextBufferFrom(FSynEdits[0]);
+  SetLines(TestText1);
+  PushBaseName('2 shared');
+
+  PushBaseName('');
+  for e1 := 0 to 1 do begin
+    for e2 := 0 to 1 do begin
+      PopPushBaseName('e1='+IntToStr(e1) + ' e2='+IntToStr(e2) );
+      // Set Mark
+      FSynEdits[e1].SetBookMark(1, 2, 4);
+      CheckBMarks('bm 1', 0, [ 4, 1  ]);
+      CheckBMarks('bm 1', 1, [ 4, 1  ]);
+
+      // goto
+      SelectEdit(0);
+      SynEdit.GotoBookMark(1);
+      TestIsCaret('Goto1 /0', 2, 4);
+      SelectEdit(1);
+      SynEdit.GotoBookMark(1);
+      TestIsCaret('Goto1 /1', 2, 4);
+
+      // clear
+      FSynEdits[e2].ClearBookMark(1);
+      CheckBMarks('bm clear', 0, [] );
+      CheckBMarks('bm clear', 1, [] );
+    end;
+  end;
+  PopBaseName;
+
+  PushBaseName('');
+  for e1 := 0 to 1 do begin
+    for e2 := 0 to 1 do begin
+      for e3 := 0 to 1 do begin
+        PopPushBaseName('e1='+IntToStr(e1) + ' e2='+IntToStr(e2) + ' e3='+IntToStr(e3));
+        FSynEdits[e1].ClearBookMark(1);
+        FSynEdits[e1].ClearBookMark(2);
+        // set 1 on ed1
+        FSynEdits[e1].SetBookMark(1, 2, 4);
+        CheckBMarks('bm set 1', 0, [ 4, 1  ]);
+        CheckBMarks('bm set 1', 1, [ 4, 1  ]);
+
+        // set 2 on ed2
+        FSynEdits[e2].SetBookMark(2, 2, 5);
+        CheckBMarks('bm set 2', 0, [ 4,1,   5,2  ]);
+        CheckBMarks('bm set 2', 1, [ 4,1,   5,2  ]);
+
+        // move 1 on ed3
+        FSynEdits[e3].SetBookMark(1, 2, 3);
+        CheckBMarks('bm move 1', 0, [ 3,1,   5,2  ]);
+        CheckBMarks('bm move 1', 1, [ 3,1,   5,2  ]);
+
+        // move 2 over 1 on ed3
+        FSynEdits[e3].SetBookMark(2, 3, 3);
+        CheckBMarks('bm move 2 over 1', 0, [ 3,2  ]);
+        CheckBMarks('bm move 2 over 1', 1, [ 3,2  ]);
+      end;
+    end;
+  end;
+  PopBaseName;
+  {%endregion}
+
+
+  {%region edits shared after bookmark set }
+  ReCreateEdit(2);
+  // default setting is shared marklist
+  FSynEdits[1].ShareOptions := [eosShareMarks];
+  SetLines(TestText1);
+  PopPushBaseName('2 shared after bm set');
+
+  FSynEdits[0].SetBookMark(1, 2, 4);
+  CheckBMarks('bm 1', 0, [ 4, 1  ]);
+  CheckBMarks('bm 1', 1, [  ]);
+
+  FSynEdits[1].ShareTextBufferFrom(FSynEdits[0]);
+
+  CheckBMarks('bm shared 1', 0, [ 4, 1  ]);
+  CheckBMarks('bm shared 1', 1, [ 4, 1  ]);
+
+  FSynEdits[1].ClearBookMark(1);
+
+  CheckBMarks('clear', 0, []);
+  CheckBMarks('clear', 1, []);
+
+  // unshare edits
+  FSynEdits[0].SetBookMark(1, 2, 4);
+  CheckBMarks('bm 1', 0, [ 4, 1  ]);
+  CheckBMarks('bm 1', 1, [ 4, 1  ]);
+
+  FSynEdits[1].UnShareTextBuffer;
+  CheckBMarks('unshare 1', 0, [ 4, 1  ]);
+  CheckBMarks('unshare 1', 1, [  ]);
+
+  FSynEdits[1].ClearBookMark(1);
+  CheckBMarks('unshare 1', 0, [ 4, 1  ]);  // not affected
+  CheckBMarks('unshare 1', 1, [  ]);
+
+  FSynEdits[0].ClearBookMark(1);
+  CheckBMarks('unshare 1', 0, [  ]);
+  CheckBMarks('unshare 1', 1, [  ]);
+  {%endregion}
+end;
+
 initialization
 
   RegisterTest(TTestSynSharedEdits);