diff --git a/nixos/tests/budgie.nix b/nixos/tests/budgie.nix
index 04e5300ec4fb..a6c40f6a9ab4 100644
--- a/nixos/tests/budgie.nix
+++ b/nixos/tests/budgie.nix
@@ -68,6 +68,8 @@
           cmd = "xargs --null --max-args=1 echo < /proc/$(pgrep -xf /run/current-system/sw/bin/budgie-wm)/environ"
           machine.succeed(f"{cmd} | grep 'XDG_CURRENT_DESKTOP' | grep 'Budgie:GNOME'")
           machine.succeed(f"{cmd} | grep 'BUDGIE_PLUGIN_DATADIR' | grep '${pkgs.budgie-desktop-with-plugins.pname}'")
+          # From the nixos/budgie module
+          machine.succeed(f"{cmd} | grep 'SSH_AUTH_SOCK' | grep 'gcr'")
 
       with subtest("Open run dialog"):
           machine.send_key("alt-f2")
diff --git a/nixos/tests/cinnamon-wayland.nix b/nixos/tests/cinnamon-wayland.nix
index a80199956cc2..d19ac920b388 100644
--- a/nixos/tests/cinnamon-wayland.nix
+++ b/nixos/tests/cinnamon-wayland.nix
@@ -58,6 +58,13 @@
       with subtest("Check if sessionPath option actually works"):
           machine.succeed("${eval "imports.gi.GIRepository.Repository.get_search_path\\(\\)"} | grep gpaste")
 
+      with subtest("Check if various environment variables are set"):
+          cmd = "xargs --null --max-args=1 echo < /proc/$(pgrep -xf /run/current-system/sw/bin/nemo-desktop)/environ"
+          machine.succeed(f"{cmd} | grep 'XDG_SESSION_TYPE' | grep 'wayland'")
+          machine.succeed(f"{cmd} | grep '__NIXOS_SET_ENVIRONMENT_DONE' | grep '1'")
+          # From the nixos/cinnamon module
+          machine.succeed(f"{cmd} | grep 'SSH_AUTH_SOCK' | grep 'gcr'")
+
       with subtest("Open Cinnamon Settings"):
           machine.succeed("${su "cinnamon-settings themes >&2 &"}")
           machine.wait_until_succeeds("${eval "global.display.focus_window.wm_class"} | grep -i 'cinnamon-settings'")
diff --git a/nixos/tests/cinnamon.nix b/nixos/tests/cinnamon.nix
index 3230d7b07358..9ff43a8dbbb7 100644
--- a/nixos/tests/cinnamon.nix
+++ b/nixos/tests/cinnamon.nix
@@ -69,6 +69,13 @@
       with subtest("Check if sessionPath option actually works"):
           machine.succeed("${eval "imports.gi.GIRepository.Repository.get_search_path\\(\\)"} | grep gpaste")
 
+      with subtest("Check if various environment variables are set"):
+          cmd = "xargs --null --max-args=1 echo < /proc/$(pgrep -xf /run/current-system/sw/bin/nemo-desktop)/environ"
+          machine.succeed(f"{cmd} | grep 'XDG_SESSION_TYPE' | grep 'x11'")
+          machine.succeed(f"{cmd} | grep '__NIXOS_SET_ENVIRONMENT_DONE' | grep '1'")
+          # From the nixos/cinnamon module
+          machine.succeed(f"{cmd} | grep 'SSH_AUTH_SOCK' | grep 'gcr'")
+
       with subtest("Open Cinnamon Settings"):
           machine.succeed("${su "cinnamon-settings themes >&2 &"}")
           machine.wait_until_succeeds("${eval "global.display.focus_window.wm_class"} | grep -i 'cinnamon-settings'")
diff --git a/nixos/tests/mate-wayland.nix b/nixos/tests/mate-wayland.nix
index 42b88439357a..c2e0ee1feaf7 100644
--- a/nixos/tests/mate-wayland.nix
+++ b/nixos/tests/mate-wayland.nix
@@ -52,6 +52,8 @@
           machine.succeed(f"{cmd} | grep 'XDG_SESSION_TYPE' | grep 'wayland'")
           machine.succeed(f"{cmd} | grep 'XDG_SESSION_DESKTOP' | grep 'MATE'")
           machine.succeed(f"{cmd} | grep 'MATE_PANEL_APPLETS_DIR' | grep '${pkgs.mate.mate-panel-with-applets.pname}'")
+          # From the nixos/mate module
+          machine.succeed(f"{cmd} | grep 'SSH_AUTH_SOCK' | grep 'gcr'")
 
       with subtest("Check if Wayfire config is properly configured"):
           for i in ["button_style = mate", "firedecor", "mate-wayland-components.sh"]:
diff --git a/nixos/tests/mate.nix b/nixos/tests/mate.nix
index 6112044837db..45fd877c1ca4 100644
--- a/nixos/tests/mate.nix
+++ b/nixos/tests/mate.nix
@@ -58,6 +58,8 @@
           machine.succeed("xargs --null --max-args=1 echo < /proc/$(pgrep -xf marco)/environ | grep 'XDG_CURRENT_DESKTOP' | grep 'MATE'")
           # From mate-panel-with-applets packaging
           machine.succeed("xargs --null --max-args=1 echo < /proc/$(pgrep -xf mate-panel)/environ | grep 'MATE_PANEL_APPLETS_DIR' | grep '${pkgs.mate.mate-panel-with-applets.pname}'")
+          # From the nixos/mate module
+          machine.succeed("xargs --null --max-args=1 echo < /proc/$(pgrep -xf mate-panel)/environ | grep 'SSH_AUTH_SOCK' | grep 'gcr'")
 
       with subtest("Check if applets are built with in-process support"):
           # This is needed for Wayland support
diff --git a/nixos/tests/pantheon-wayland.nix b/nixos/tests/pantheon-wayland.nix
index 6bda9e508ef2..87c8b17a692c 100644
--- a/nixos/tests/pantheon-wayland.nix
+++ b/nixos/tests/pantheon-wayland.nix
@@ -78,6 +78,8 @@
           machine.succeed(f"{cmd} | grep 'XDG_DATA_DIRS' | grep 'gsettings-schemas/pantheon-agent-geoclue2'")
           # Hopefully from login shell.
           machine.succeed(f"{cmd} | grep '__NIXOS_SET_ENVIRONMENT_DONE' | grep '1'")
+          # Hopefully from gcr-ssh-agent.
+          machine.succeed(f"{cmd} | grep 'SSH_AUTH_SOCK' | grep 'gcr'")
 
       with subtest("Wait for elementary videos autostart"):
           machine.wait_until_succeeds("pgrep -f io.elementary.videos")
diff --git a/nixos/tests/pantheon.nix b/nixos/tests/pantheon.nix
index b8cb0512c542..855d0f48f80c 100644
--- a/nixos/tests/pantheon.nix
+++ b/nixos/tests/pantheon.nix
@@ -73,6 +73,8 @@
           machine.succeed(f"{cmd} | grep 'XDG_DATA_DIRS' | grep 'gsettings-schemas/pantheon-agent-geoclue2'")
           # Hopefully from login shell.
           machine.succeed(f"{cmd} | grep '__NIXOS_SET_ENVIRONMENT_DONE' | grep '1'")
+          # Hopefully from gcr-ssh-agent.
+          machine.succeed(f"{cmd} | grep 'SSH_AUTH_SOCK' | grep 'gcr'")
 
       with subtest("Open elementary videos"):
           machine.execute("su - ${user.name} -c 'DISPLAY=:0 io.elementary.videos >&2 &'")