diff --git a/server/default.nix b/server/default.nix
index 8ccd559..90e104d 100644
--- a/server/default.nix
+++ b/server/default.nix
@@ -138,6 +138,7 @@ in
     hunspellDicts.en_US
     isync
     lsb-release
+    lsof
     pkg-config
     poppler_utils
     ruby