diff --git a/pkgs/applications/networking/browsers/firefox-bin/default.nix b/pkgs/applications/networking/browsers/firefox-bin/default.nix
index 725205c5c209..d16c625e2dba 100644
--- a/pkgs/applications/networking/browsers/firefox-bin/default.nix
+++ b/pkgs/applications/networking/browsers/firefox-bin/default.nix
@@ -203,6 +203,7 @@ stdenv.mkDerivation {
       url = "http://www.mozilla.org/en-US/foundation/trademarks/policy/";
     };
     platforms = builtins.attrNames mozillaPlatforms;
+    timeout = 86400; # 24 hours (increased from the Hydra default of 10h, c.f. #129115)
     maintainers = with maintainers; [ taku0 lovesegfault ];
   };
 }