diff --git a/pkgs/servers/monitoring/alerta/default.nix b/pkgs/servers/monitoring/alerta/default.nix
index c3758c26b253..795ae560f0be 100644
--- a/pkgs/servers/monitoring/alerta/default.nix
+++ b/pkgs/servers/monitoring/alerta/default.nix
@@ -14,6 +14,7 @@ python3.pkgs.buildPythonApplication rec {
   propagatedBuildInputs = with python3.pkgs; [
     bcrypt
     blinker
+    cryptography
     flask
     flask-compress
     flask-cors