diff --git a/pkgs/by-name/pr/pretalx/package.nix b/pkgs/by-name/pr/pretalx/package.nix
index 78fdd3f34b66..c6bc70cca039 100644
--- a/pkgs/by-name/pr/pretalx/package.nix
+++ b/pkgs/by-name/pr/pretalx/package.nix
@@ -93,6 +93,7 @@ python.pkgs.buildPythonApplication rec {
   ];
 
   pythonRelaxDeps = [
+    "bleach"
     "celery"
     "css-inline"
     "cssutils"