diff --git a/hosts/FredOS-Macbook.nix b/hosts/FredOS-Macbook.nix
index 2fe7561..b27fed2 100644
--- a/hosts/FredOS-Macbook.nix
+++ b/hosts/FredOS-Macbook.nix
@@ -49,6 +49,8 @@ import glob, os, select, struct, time
 EVENT_SIZE = struct.calcsize("llHHi")
 EV_KEY = 0x01
 DWT_TIMEOUT = 0.3
+# Modifier keycodes — don't inhibit touchpad for these
+MODIFIERS = {42, 54, 29, 97, 56, 100, 125, 126}  # L/R Shift, Ctrl, Alt, Super
 
 def find_event(name):
     for p in sorted(glob.glob("/sys/class/input/event*/device/name")):
@@ -75,8 +77,8 @@ def main():
                 if r:
                     data = os.read(f.fileno(), EVENT_SIZE * 64)
                     for off in range(0, len(data) - EVENT_SIZE + 1, EVENT_SIZE):
-                        _, _, typ, _, val = struct.unpack("llHHi", data[off:off + EVENT_SIZE])
-                        if typ == EV_KEY and val:
+                        _, _, typ, code, val = struct.unpack("llHHi", data[off:off + EVENT_SIZE])
+                        if typ == EV_KEY and val and code not in MODIFIERS:
                             last_key = time.monotonic()
                             if not active:
                                 open(inhibit, "w").write("1")