diff --git a/desktop.nix b/desktop.nix
index 98522cb..596a056 100644
--- a/desktop.nix
+++ b/desktop.nix
@@ -135,6 +135,30 @@
     windowManager.awesome.enable = true;
     startGnuPGAgent = true;
     startOpenSSHAgent = false; # pas compatible avec l'agent GnuPG
+    inputClassSections = [''
+    Identifier  "Marble Mouse"
+    MatchProduct "Logitech USB Trackball"
+    MatchIsPointer "on"
+    MatchDevicePath "/dev/input/event*"
+    Driver "evdev"
+    # Physical button #s:     A b D - - - - B C    b = A & D simultaneously;   - = no button
+    #Option "ButtonMapping" "1 8 3 4 5 6 7 2 2"   #  For right-hand placement
+    #Option "ButtonMapping" "3 8 1 4 5 6 7 2 2"   #  For left-hand placement
+
+    # EmulateWheel refers to emulating a mouse wheel using Marble Mouse trackball.
+    Option "EmulateWheel" "true"
+    Option "EmulateWheelButton" "8"   # Factory default; use "9" for left-side placement.
+
+    # EmulateWheelInertia specifies how far (in pixels) the pointer must move to
+    # generate button press/release events in wheel emulation mode.
+    Option "EmulateWheelInertia" "10" # Factory default: 50
+
+    Option "ZAxisMapping" "4 5"
+    Option "XAxisMapping" "6 7"       # Disable this for vertical-only scrolling.
+    # Emulate3Buttons refers to the act of pressing buttons A and D
+    # simultaneously to emulate a middle-click or wheel click.
+    Option "Emulate3Buttons" "true"   # Factory default.
+    ''];
   };
 
   hardware.pulseaudio = {