diff --git a/bin/omarchy-hw-external-monitors b/bin/omarchy-hw-external-monitors
index 3a5a837f..9c75a97a 100755
--- a/bin/omarchy-hw-external-monitors
+++ b/bin/omarchy-hw-external-monitors
@@ -2,8 +2,11 @@
 
 # omarchy:summary=Returns true when an external monitor is physically connected.
 
-for status in /sys/class/drm/card*-*/status; do
-  [[ $status == *-eDP-*/status ]] && continue
+drm_path="${OMARCHY_DRM_PATH:-/sys/class/drm}"
+
+for status in "$drm_path"/card*-*/status; do
+  [[ -e $status ]] || continue
+  [[ $status =~ -(eDP|LVDS|DSI)-[^/]+/status$ ]] && continue
   [[ $(< $status) == "connected" ]] && exit 0
 done
 exit 1
diff --git a/test/shell.d/hw-external-monitors-test.sh b/test/shell.d/hw-external-monitors-test.sh
new file mode 100644
index 00000000..b632f680
--- /dev/null
+++ b/test/shell.d/hw-external-monitors-test.sh
@@ -0,0 +1,61 @@
+#!/bin/bash
+
+set -euo pipefail
+
+source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/base-test.sh"
+
+test_tmp=$(mktemp -d)
+trap 'rm -rf "$test_tmp"' EXIT
+
+drm_path="$test_tmp/drm"
+
+write_connectors() {
+  rm -rf "$drm_path"
+  mkdir -p "$drm_path"
+
+  local connector state
+  while (( $# )); do
+    connector="$1"
+    state="$2"
+    mkdir -p "$drm_path/card0-$connector"
+    printf '%s\n' "$state" >"$drm_path/card0-$connector/status"
+    shift 2
+  done
+}
+
+has_external_monitor() {
+  OMARCHY_DRM_PATH="$drm_path" "$ROOT/bin/omarchy-hw-external-monitors"
+}
+
+write_connectors
+set +e
+empty_error=$(has_external_monitor 2>&1 >/dev/null)
+empty_status=$?
+set -e
+
+(( empty_status != 0 )) || fail "an empty DRM tree has no external display"
+[[ -z $empty_error ]] || fail "an empty DRM tree is handled quietly" "$empty_error"
+pass "physical monitor detection handles an empty DRM tree"
+
+for connector in eDP-1 LVDS-1 DSI-1; do
+  write_connectors "$connector" connected
+
+  if has_external_monitor; then
+    fail "$connector is treated as an internal display"
+  fi
+done
+pass "physical monitor detection ignores common internal panel connectors"
+
+write_connectors LVDS-1 connected DP-1 connected
+has_external_monitor || fail "external display is found alongside an LVDS panel"
+pass "physical monitor detection finds an external display alongside an LVDS panel"
+
+write_connectors eDP-1 connected HDMI-A-1 disconnected
+if has_external_monitor; then
+  fail "a disconnected external display is not reported as connected"
+fi
+pass "physical monitor detection ignores disconnected external displays"
+
+write_connectors DP-1 connected
+has_external_monitor || fail "external-only systems still report a connected display"
+pass "physical monitor detection still supports external-only systems"