diff --git a/pkgs/desktops/gnome-3/misc/geary/default.nix b/pkgs/desktops/gnome-3/misc/geary/default.nix
index 787bdd97ebf8..07319337a9a0 100644
--- a/pkgs/desktops/gnome-3/misc/geary/default.nix
+++ b/pkgs/desktops/gnome-3/misc/geary/default.nix
@@ -1,6 +1,6 @@
 { stdenv, fetchurl, pkgconfig, gtk3, vala, enchant2, wrapGAppsHook, meson, ninja
 , desktop-file-utils, gnome-online-accounts, gsettings-desktop-schemas, adwaita-icon-theme
-, libcanberra-gtk3, libsecret, gmime, isocodes, libxml2, gettext
+, libcanberra-gtk3, libsecret, gmime, isocodes, libxml2, gettext, fetchpatch
 , sqlite, gcr, json-glib, itstool, libgee, gnome3, webkitgtk, python3
 , xvfb_run, dbus, shared-mime-info, libunwind, libunity, folks, glib-networking
 , gobject-introspection, gspell, appstream-glib, libytnef, libhandy }:
@@ -33,6 +33,14 @@ stdenv.mkDerivation rec {
     "-Dcontractor=true" # install the contractor file (Pantheon specific)
   ];
 
+  patches = [
+    # Longer timeout for client test.
+    (fetchpatch {
+      url = "https://salsa.debian.org/gnome-team/geary/raw/04be1e058a2e65075dd8cf8843d469ee45a9e09a/debian/patches/Bump-client-test-timeout-to-300s.patch";
+      sha256 = "1zvnq8bgla160531bjdra8hcg15mp8r1j1n53m1xfgm0ssnj5knx";
+    })
+  ];
+
   postPatch = ''
     chmod +x build-aux/post_install.py build-aux/git_version.py
     patchShebangs build-aux/post_install.py build-aux/git_version.py