diff --git a/components/wiki/lazwiki/wiki2xhtmlconvert.pas b/components/wiki/lazwiki/wiki2xhtmlconvert.pas
index 086eaf3e8d..ce520dd7ef 100644
--- a/components/wiki/lazwiki/wiki2xhtmlconvert.pas
+++ b/components/wiki/lazwiki/wiki2xhtmlconvert.pas
@@ -145,14 +145,14 @@ var
   category, url, txt: String;
   i: Integer;
 begin
-  if FCategoryList.Count = 0 then
-    exit;
-
   doc := Page.XHTML;
   url := Page.WikiPage.BaseURL;
   if (url <> '') and (url[Length(url)] <> '/') then
     url += '/';
 
+  if Page.CategoryList.Count = 0 then
+    exit;
+
   CategoriesNode := doc.CreateElement('div');
   CategoriesNode.SetAttribute('class', 'categories');
   Page.BodyDOMNode.AppendChild(CategoriesNode);
@@ -165,8 +165,8 @@ begin
   if not FIndexInternalLinksOnly then
     AddIndexItem('Categories (external)', url+'Special:Categories');
 
-  for i:=0 to FCategoryList.Count-1 do begin
-    category := FCategoryList[i];
+  for i:=0 to Page.CategoryList.Count-1 do begin
+    category := Page.CategoryList[i];
     // Add link to category
     node := doc.CreateElement('a');
     node.SetAttribute('href', url + category);
@@ -177,7 +177,7 @@ begin
       AddIndexItem('Category: '+txt+' (external)', url+category);
 
     // Add separator
-    if i < FCategoryList.Count-1 then
+    if i < Page.CategoryList.Count-1 then
       CategoriesNode.AppendChild(doc.CreateTextNode(' | '));
   end;
 end;
@@ -532,7 +532,7 @@ var
         exit;
       end
       else if Scheme='category' then begin
-        FCategoryList.Add(URL);
+        Page.CategoryList.Add(URL);
         URL:='';
         Caption := '';
         exit;
diff --git a/components/wiki/lazwiki/wikiformat.pas b/components/wiki/lazwiki/wikiformat.pas
index 8d767194b7..06c632cc8d 100644
--- a/components/wiki/lazwiki/wikiformat.pas
+++ b/components/wiki/lazwiki/wikiformat.pas
@@ -39,6 +39,7 @@ type
   TW2FormatPage = class
   public
     Converter: TWiki2FormatConverter;
+    CategoryList: TStringList;
     WikiFilename: string;
     WikiErrorMsg: string;
     WikiDoc: TXMLDocument;
@@ -72,7 +73,6 @@ type
     fPagesSortFilename: TAvgLvlTree; // TW2FormatPage sorted for WikiFilename
     fPagesSortDocumentName: TAvgLvlTree; // TW2FormatPage sorted for WikiDocumentName
     FPageClass: TW2FormatPageClass;
-    FCategoryList: TStringList;
     function GetPages(Index: integer): TW2FormatPage;
     procedure SetOutputDir(AValue: string);
     procedure SetImagesDir(AValue: string);
@@ -169,13 +169,11 @@ begin
   FTitle:='FPC/Lazarus Wiki (offline, generated '+DatetoStr(Now)+')';
   FImagesDir:='images';
   FNoWarnBaseURLs:=TStringToStringTree.Create(true);
-  FCategoryList := TStringList.Create;
 end;
 
 destructor TWiki2FormatConverter.Destroy;
 begin
   Clear;
-  FreeAndNil(FCategoryList);
   FreeAndNil(FNoWarnBaseURLs);
   FreeAndNil(fPagesSortFilename);
   FreeAndNil(fPagesSortDocumentName);
@@ -312,12 +310,14 @@ end;
 constructor TW2FormatPage.Create(TheConverter: TWiki2FormatConverter);
 begin
   Converter:=TheConverter;
+  CategoryList := TStringList.Create;
 end;
 
 destructor TW2FormatPage.Destroy;
 begin
   ClearPageConnections;
   ClearConversion;
+  FreeAndNil(CategoryList);
   FreeAndNil(WikiDoc);
   FreeAndNil(WikiPage);
   inherited Destroy;