diff --git a/pkgs/by-name/gn/gns3-gui/package.nix b/pkgs/by-name/gn/gns3-gui/package.nix
index e147afc1ee32..2d1af2ba0725 100644
--- a/pkgs/by-name/gn/gns3-gui/package.nix
+++ b/pkgs/by-name/gn/gns3-gui/package.nix
@@ -1,48 +1,51 @@
 {
   fetchFromGitHub,
+  fetchpatch,
   gns3-gui,
   lib,
   python3Packages,
-  qt5,
+  qt6,
   testers,
   writableTmpDirAsHomeHook,
 }:
 
-let
-  pythonPackages = python3Packages.overrideScope (
-    final: prev: {
-      pyqt5 = prev.pyqt5.override { withWebSockets = true; };
-    }
-  );
-in
-pythonPackages.buildPythonApplication rec {
+python3Packages.buildPythonApplication rec {
   pname = "gns3-gui";
-  version = "2.2.55";
+  version = "2.2.56.1";
   pyproject = true;
 
   src = fetchFromGitHub {
     owner = "GNS3";
     repo = "gns3-gui";
     tag = "v${version}";
-    hash = "sha256-6jblQakNpoSQXfy5pU68Aedg661VcwpqQilvqOV15pQ";
+    hash = "sha256-HBTBwn7jAW/SXFTfPbO08bDG5NfS3tuic/Z0ib1/Uo8=";
   };
 
+  patches = [
+    # Fix tests after PyQt6 migration
+    (fetchpatch {
+      url = "https://github.com/GNS3/gns3-gui/commit/e6e2a1cafbc3ce4be9cca3428e60400f25806cde.patch";
+      hash = "sha256-T15OCqm+Te9ZOCg/kFf/fd2DY75LfaLHskAAgGYMloI=";
+    })
+  ];
+
   pythonRelaxDeps = [
     "jsonschema"
+    "psutil"
     "sentry-sdk"
   ];
 
-  nativeBuildInputs = [ qt5.wrapQtAppsHook ];
+  nativeBuildInputs = [ qt6.wrapQtAppsHook ];
 
-  buildInputs = [ qt5.qtwayland ];
+  buildInputs = [ qt6.qtwayland ];
 
-  build-system = with pythonPackages; [ setuptools ];
+  build-system = with python3Packages; [ setuptools ];
 
-  dependencies = with pythonPackages; [
+  dependencies = with python3Packages; [
     distro
     jsonschema
     psutil
-    pyqt5
+    pyqt6
     sentry-sdk
     setuptools
     sip
@@ -55,14 +58,13 @@ pythonPackages.buildPythonApplication rec {
     makeWrapperArgs+=("''${qtWrapperArgs[@]}")
   '';
 
-  nativeCheckInputs = with pythonPackages; [
+  nativeCheckInputs = with python3Packages; [
     pytestCheckHook
     writableTmpDirAsHomeHook
   ];
 
   preCheck = ''
-    export QT_PLUGIN_PATH="${lib.getBin qt5.qtbase}/${qt5.qtbase.qtPluginPrefix}"
-    export QT_QPA_PLATFORM_PLUGIN_PATH="${lib.getBin qt5.qtbase}/lib/qt-${qt5.qtbase.version}/plugins";
+    export QT_PLUGIN_PATH="${lib.getBin qt6.qtbase}/${qt6.qtbase.qtPluginPrefix}"
     export QT_QPA_PLATFORM=offscreen
   '';