diff --git a/pkgs/development/python-modules/karton-dashboard/default.nix b/pkgs/development/python-modules/karton-dashboard/default.nix
index 986c7ec27b6a..a055c423374b 100644
--- a/pkgs/development/python-modules/karton-dashboard/default.nix
+++ b/pkgs/development/python-modules/karton-dashboard/default.nix
@@ -8,6 +8,7 @@
 , networkx
 , prometheus-client
 , pythonOlder
+, pythonRelaxDepsHook
 }:
 
 buildPythonPackage rec {
@@ -25,6 +26,7 @@ buildPythonPackage rec {
   };
 
   patches = [
+    # Allow later mistune, https://github.com/CERT-Polska/karton-dashboard/pull/68
     (fetchpatch {
       name = "update-mistune.patch";
       url = "https://github.com/CERT-Polska/karton-dashboard/commit/d0a2a1ffd21e9066acca77434acaff7b20e460d0.patch";
@@ -32,6 +34,17 @@ buildPythonPackage rec {
     })
   ];
 
+  pythonRelaxDeps = [
+    "Flask"
+    "mistune"
+    "networkx"
+    "prometheus-client"
+  ];
+
+  nativeBuildInputs = [
+    pythonRelaxDepsHook
+  ];
+
   propagatedBuildInputs = [
     flask
     karton-core
@@ -40,13 +53,6 @@ buildPythonPackage rec {
     prometheus-client
   ];
 
-  postPatch = ''
-    substituteInPlace requirements.txt \
-      --replace "Flask==2.0.3" "Flask" \
-      --replace "networkx==2.6.3" "networkx" \
-      --replace "prometheus_client==0.11.0" "prometheus_client"
-  '';
-
   # Project has no tests. pythonImportsCheck requires MinIO configuration
   doCheck = false;