diff --git a/libs/wxutil/dataview/ResourceTreeView.cpp b/libs/wxutil/dataview/ResourceTreeView.cpp
index b7e6f41543..fa577665ee 100644
--- a/libs/wxutil/dataview/ResourceTreeView.cpp
+++ b/libs/wxutil/dataview/ResourceTreeView.cpp
@@ -5,7 +5,6 @@
 #include "ifavourites.h"
 #include "../menu/IconTextMenuItem.h"
 #include "TreeViewItemStyle.h"
-#include "string/case_conv.h"
 #include <wx/artprov.h>
 
 namespace wxutil
@@ -200,10 +199,10 @@ void ResourceTreeView::PopulateContextMenu(wxutil::PopupMenu& popupMenu)
     );
 }
 
-void ResourceTreeView::SetFilterText(const std::string& filterText)
+void ResourceTreeView::SetFilterText(const wxString& filterText)
 {
     // We use the lower-case copy of the given filter text
-    _filterText = string::to_lower_copy(filterText);
+    _filterText = filterText.Lower();
 
     wxDataViewItem item = GetSelection();
 
@@ -525,10 +524,9 @@ bool ResourceTreeView::RowContainsSearchString(wxutil::TreeModel::Row& row)
 {
     wxDataViewIconText iconAndName = row[_columns.iconAndName];
 
-    auto displayString = iconAndName.GetText().ToStdString();
-    string::to_lower(displayString);
+    auto displayString = iconAndName.GetText().Lower();
 
-    return displayString.find(_filterText) != std::string::npos;
+    return displayString.Contains(_filterText);
 }
 
 bool ResourceTreeView::IsTreeModelRowFilteredRecursively(wxutil::TreeModel::Row& row)
diff --git a/libs/wxutil/dataview/ResourceTreeView.h b/libs/wxutil/dataview/ResourceTreeView.h
index 8a573ce40c..3fb35f4a6a 100644
--- a/libs/wxutil/dataview/ResourceTreeView.h
+++ b/libs/wxutil/dataview/ResourceTreeView.h
@@ -88,7 +88,7 @@ class ResourceTreeView :
 
     decl::Type _declType;
 
-    std::string _filterText;
+    wxString _filterText;
 
 public:
     ResourceTreeView(wxWindow* parent, const Columns& columns, long style = wxDV_SINGLE);
@@ -107,7 +107,7 @@ class ResourceTreeView :
     // this string will match against the default iconAndName column,
     // all rows not containing the string will be hidden.
     // Filtering happens case-insensitively.
-    virtual void SetFilterText(const std::string& filterText);
+    virtual void SetFilterText(const wxString& filterText);
 
     // Removes the string filter
     virtual void ClearFilterText();
diff --git a/libs/wxutil/dataview/ResourceTreeViewToolbar.cpp b/libs/wxutil/dataview/ResourceTreeViewToolbar.cpp
index c865d6c79f..e3a5eafff4 100644
--- a/libs/wxutil/dataview/ResourceTreeViewToolbar.cpp
+++ b/libs/wxutil/dataview/ResourceTreeViewToolbar.cpp
@@ -44,7 +44,7 @@ ResourceTreeViewToolbar::ResourceTreeViewToolbar(wxWindow* parent, ResourceTreeV
     {
         if (_treeView != nullptr)
         {
-            _treeView->SetFilterText(ev.GetString().ToStdString());
+            _treeView->SetFilterText(ev.GetString());
         }
     });
     filterEntry->Bind(wxEVT_CHAR, &ResourceTreeViewToolbar::_onEntryChar, this);