diff --git a/pkgs/development/python-modules/vdirsyncer/default.nix b/pkgs/development/python-modules/vdirsyncer/default.nix
index 70446323f1d9..b9046f991f6c 100644
--- a/pkgs/development/python-modules/vdirsyncer/default.nix
+++ b/pkgs/development/python-modules/vdirsyncer/default.nix
@@ -22,6 +22,7 @@
 , aioresponses
 , vdirsyncer
 , testers
+, pythonRelaxDepsHook
 }:
 
 buildPythonPackage rec {
@@ -44,6 +45,11 @@ buildPythonPackage rec {
     setuptools
     setuptools-scm
     wheel
+    pythonRelaxDepsHook
+  ];
+
+  pythonRelaxDeps = [
+    "aiostream"
   ];
 
   propagatedBuildInputs = [