diff --git a/components/synedit/synguttermarks.pp b/components/synedit/synguttermarks.pp
index 5be230f1d5..d0b55e7cb4 100644
--- a/components/synedit/synguttermarks.pp
+++ b/components/synedit/synguttermarks.pp
@@ -24,7 +24,7 @@ type
     procedure Init; override;
     function  PreferedWidth: Integer; override;
     function GetImgListRes(const ACanvas: TCanvas;
-      const AImages: TCustomImageList): TScaledImageListResolution;
+      const AImages: TCustomImageList): TScaledImageListResolution; virtual;
     // PaintMarks: True, if it has any Mark, that is *not* a bookmark
     function  PaintMarks(aScreenLine: Integer; Canvas : TCanvas; AClip : TRect;
                        var aFirstCustomColumnIdx: integer): Boolean;
diff --git a/ide/sourcesyneditor.pas b/ide/sourcesyneditor.pas
index 944edc71a9..ae3a3e1cf7 100644
--- a/ide/sourcesyneditor.pas
+++ b/ide/sourcesyneditor.pas
@@ -275,6 +275,7 @@ type
     function CreateGutter(AOwner : TSynEditBase; ASide: TSynGutterSide;
                           ATextDrawer: TheTextDrawer): TSynGutter; override;
     procedure SetHighlighter(const Value: TSynCustomHighlighter); override;
+    procedure FontChanged(Sender: TObject); override;
   public
     constructor Create(AOwner: TComponent); override;
     destructor Destroy; override;
@@ -436,6 +437,9 @@ type
     procedure CheckTextBuffer;       // Todo: Add a notification, when TextBuffer Changes
     Procedure PaintLine(aScreenLine: Integer; Canvas : TCanvas; AClip : TRect); override;
     function PreferedWidth: Integer; override;
+
+    function GetImgListRes(const ACanvas: TCanvas;
+      const AImages: TCustomImageList): TScaledImageListResolution; override;
   public
     destructor Destroy; override;
     procedure BeginSetDebugMarks;
@@ -1538,6 +1542,13 @@ begin
   {$pop}
 end;
 
+procedure TIDESynEditor.FontChanged(Sender: TObject);
+begin
+  FLeftGutterArea.Gutter.DoAutoSize;
+  FRightGutterArea.Gutter.DoAutoSize;
+  inherited FontChanged(Sender);
+end;
+
 procedure TIDESynEditor.GetTopInfoMarkupForLine(Sender: TObject; Line: integer;
   var Special: boolean; aMarkup: TSynSelectedColor);
 begin
@@ -2165,47 +2176,52 @@ end;
 
 procedure TIDESynGutter.CreateDefaultGutterParts;
 begin
-  if Side = gsLeft then begin
-    with TIDESynGutterMarks.Create(Parts) do
-      Name := 'SynGutterMarks1';
-    with TSynGutterLineNumber.Create(Parts) do
-      Name := 'SynGutterLineNumber1';
-    with TSynGutterChanges.Create(Parts) do
-      Name := 'SynGutterChanges1';
-    with TSynGutterSeparator.Create(Parts) do
-      Name := 'SynGutterSeparator1';
-    with TIDESynGutterCodeFolding.Create(Parts) do
-      Name := 'SynGutterCodeFolding1';
-  end
-  else begin
-    {$IFDEF WithSynDebugGutter}
-    with TSynGutterSeparator.Create(Parts) do
-      Name := 'SynGutterSeparatorR1';
-    DebugGutter := TIDESynGutterDebugHL.Create(Parts);
-    with DebugGutter do
-      Name := 'TIDESynGutterDebugHL';
-    {$ENDIF}
-    with TSynGutterSeparator.Create(Parts) do
-      Name := 'SynGutterSeparatorR2';
-    with TSynGutterLineOverview.Create(Parts) do begin
-      Name := 'SynGutterLineOverview1';
-      with TIDESynGutterLOvProviderIDEMarks.Create(Providers) do
-        Priority := 20;
-      with TSynGutterLOvProviderModifiedLines.Create(Providers) do
-        Priority := 9;
-      with TSynGutterLOvProviderCurrentPage.Create(Providers) do begin
-        Priority := 1;
-        FoldedTextBuffer := TSynEditFoldedView(TIDESynEditor(Self.SynEdit).FoldedTextBuffer);
+  IncChangeLock;
+  try
+    if Side = gsLeft then begin
+      with TIDESynGutterMarks.Create(Parts) do
+        Name := 'SynGutterMarks1';
+      with TSynGutterLineNumber.Create(Parts) do
+        Name := 'SynGutterLineNumber1';
+      with TSynGutterChanges.Create(Parts) do
+        Name := 'SynGutterChanges1';
+      with TSynGutterSeparator.Create(Parts) do
+        Name := 'SynGutterSeparator1';
+      with TIDESynGutterCodeFolding.Create(Parts) do
+        Name := 'SynGutterCodeFolding1';
+    end
+    else begin
+      {$IFDEF WithSynDebugGutter}
+      with TSynGutterSeparator.Create(Parts) do
+        Name := 'SynGutterSeparatorR1';
+      DebugGutter := TIDESynGutterDebugHL.Create(Parts);
+      with DebugGutter do
+        Name := 'TIDESynGutterDebugHL';
+      {$ENDIF}
+      with TSynGutterSeparator.Create(Parts) do
+        Name := 'SynGutterSeparatorR2';
+      with TSynGutterLineOverview.Create(Parts) do begin
+        Name := 'SynGutterLineOverview1';
+        with TIDESynGutterLOvProviderIDEMarks.Create(Providers) do
+          Priority := 20;
+        with TSynGutterLOvProviderModifiedLines.Create(Providers) do
+          Priority := 9;
+        with TSynGutterLOvProviderCurrentPage.Create(Providers) do begin
+          Priority := 1;
+          FoldedTextBuffer := TSynEditFoldedView(TIDESynEditor(Self.SynEdit).FoldedTextBuffer);
+        end;
+        with TIDESynGutterLOvProviderPascal.Create(Providers) do
+          Priority := 0;
+      end;
+      with TSynGutterSeparator.Create(Parts) do begin
+        Name := 'SynGutterSeparatorR3';
+        AutoSize := False;
+        Width := 1;
+        LineWidth := 0;
       end;
-      with TIDESynGutterLOvProviderPascal.Create(Providers) do
-        Priority := 0;
-    end;
-    with TSynGutterSeparator.Create(Parts) do begin
-      Name := 'SynGutterSeparatorR3';
-      AutoSize := False;
-      Width := 1;
-      LineWidth := 0;
     end;
+  finally
+    DecChangeLock;
   end;
 end;
 
@@ -2265,10 +2281,14 @@ begin
 end;
 
 function TIDESynGutterMarks.PreferedWidth: Integer;
+var
+  img: TScaledImageListResolution;
 begin
   if Assigned(SourceEditorMarks) and Assigned(SourceEditorMarks.ImgList) then
-    Result := SourceEditorMarks.ImgList.Width * 2 + FBookMarkOpt.LeftMargin
-  else
+  begin
+    img := GetImgListRes(nil, SourceEditorMarks.ImgList);
+    Result := SynEdit.ScaleFontTo96(img.Width * 2) + FBookMarkOpt.LeftMargin; // PreferedWidth needs width at 96 PPI
+  end else
     Result := inherited PreferedWidth;
 end;
 
@@ -2300,6 +2320,43 @@ begin
   TSynEdit(SynEdit).InvalidateGutter;
 end;
 
+function TIDESynGutterMarks.GetImgListRes(const ACanvas: TCanvas;
+  const AImages: TCustomImageList): TScaledImageListResolution;
+const
+  AllowedHeights: array[0..5] of Integer = (8, 11, 16, 22, 33, 44);
+var
+  Scale: Double;
+  PPI, LineHeight, I, ImageHeight: Integer;
+begin
+  // image height must be equal to width
+  if AImages.Width<>AImages.Height then
+    raise Exception.Create('Internal error: AImages.Width<>AImages.Height');
+
+  Scale := 1;
+  PPI := 96;
+  if SynEdit is TSynEdit then
+  begin
+    LineHeight := TSynEdit(SynEdit).LineHeight;
+    ImageHeight := Low(AllowedHeights);
+    for I := High(AllowedHeights) downto Low(AllowedHeights) do
+      if AllowedHeights[I]<LineHeight then
+      begin
+        ImageHeight := AllowedHeights[I];
+        break;
+      end;
+    // don't set PPI here -> we don't want to scale the image anymore
+  end else
+  begin
+    ImageHeight := AImages.Height;
+    if ACanvas is TControlCanvas then
+      PPI := TControlCanvas(ACanvas).Control.Font.PixelsPerInch;
+  end;
+
+  if ACanvas is TControlCanvas then
+    Scale := TControlCanvas(ACanvas).Control.GetCanvasScaleFactor;
+  Result := AImages.ResolutionForPPI[ImageHeight, PPI, Scale];
+end;
+
 procedure TIDESynGutterMarks.SetDebugMarks(AFirstLinePos, ALastLinePos: Integer);
 var
   i: LongInt;