diff --git a/android/app/src/main/kotlin/dev/so1ve/bitree/TimetableWidget.kt b/android/app/src/main/kotlin/dev/so1ve/bitree/TimetableWidget.kt
index 4b5ea0d..83ea23a 100644
--- a/android/app/src/main/kotlin/dev/so1ve/bitree/TimetableWidget.kt
+++ b/android/app/src/main/kotlin/dev/so1ve/bitree/TimetableWidget.kt
@@ -4,6 +4,7 @@ import android.app.AlarmManager
 import android.app.PendingIntent
 import android.appwidget.AppWidgetManager
 import android.appwidget.AppWidgetProvider
+import android.appwidget.AppWidgetProviderInfo
 import android.content.ComponentName
 import android.content.Context
 import android.content.Intent
@@ -76,7 +77,26 @@ open class TimetableWidget : AppWidgetProvider() {
                 PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE,
             )
             widgets.forEach { (id, columns) ->
-                val views = RemoteViews(context.packageName, R.layout.timetable_widget)
+                val options = manager.getAppWidgetOptions(id)
+                val hostCategory = options.getInt(
+                    AppWidgetManager.OPTION_APPWIDGET_HOST_CATEGORY,
+                    AppWidgetProviderInfo.WIDGET_CATEGORY_HOME_SCREEN,
+                )
+                // The lock-screen host controls the slot width independently of targetCellWidth.
+                val compactKeyguard = columns == 1 &&
+                    (hostCategory and AppWidgetProviderInfo.WIDGET_CATEGORY_KEYGUARD) != 0
+                val hostWidthPx = widgetWidthPx(context, manager, id)
+                val widthPx = if (compactKeyguard) {
+                    hostWidthPx * 0.6f
+                } else {
+                    hostWidthPx
+                }
+                val layout = if (compactKeyguard) {
+                    R.layout.timetable_widget_compact_keyguard
+                } else {
+                    R.layout.timetable_widget
+                }
+                val views = RemoteViews(context.packageName, layout)
                 views.setInt(
                     R.id.widget_content, "setBackgroundColor", WidgetColors.background(context),
                 )
@@ -102,7 +122,6 @@ open class TimetableWidget : AppWidgetProvider() {
                     )
                 }
 
-                val widthPx = widgetWidthPx(context, manager, id)
                 val heightPx = widgetContentMinHeightPx(context, manager, id)
                 val items = entryItems(context, content.entries, widthPx, heightPx, columns)
 
diff --git a/android/app/src/main/res/layout/timetable_widget_compact_keyguard.xml b/android/app/src/main/res/layout/timetable_widget_compact_keyguard.xml
new file mode 100644
index 0000000..f33596a
--- /dev/null
+++ b/android/app/src/main/res/layout/timetable_widget_compact_keyguard.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="horizontal">
+    <!-- Weights keep the lock-screen slot split into 20% / 60% / 20%. -->
+    <FrameLayout
+        android:layout_width="0dp"
+        android:layout_height="match_parent"
+        android:layout_weight="1" />
+    <include
+        layout="@layout/timetable_widget"
+        android:layout_width="0dp"
+        android:layout_height="match_parent"
+        android:layout_weight="3" />
+    <FrameLayout
+        android:layout_width="0dp"
+        android:layout_height="match_parent"
+        android:layout_weight="1" />
+</LinearLayout>
diff --git a/android/app/src/main/res/layout/timetable_widget_preview.xml b/android/app/src/main/res/layout/timetable_widget_preview.xml
index 38c8e0b..4958115 100644
--- a/android/app/src/main/res/layout/timetable_widget_preview.xml
+++ b/android/app/src/main/res/layout/timetable_widget_preview.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    android:layout_width="146dp"
+    android:layout_width="@dimen/widget_compact_width"
     android:layout_height="146dp">
     <include
         layout="@layout/timetable_widget"
diff --git a/android/app/src/main/res/values/dimens.xml b/android/app/src/main/res/values/dimens.xml
index 7db9991..0d76441 100644
--- a/android/app/src/main/res/values/dimens.xml
+++ b/android/app/src/main/res/values/dimens.xml
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
+    <dimen name="widget_compact_width">146dp</dimen>
     <dimen name="widget_background_radius">14dp</dimen>
     <dimen name="widget_course_radius">6dp</dimen>
     <dimen name="widget_padding">10dp</dimen>
diff --git a/android/app/src/main/res/xml/timetable_widget_info.xml b/android/app/src/main/res/xml/timetable_widget_info.xml
index 688ebff..12444c3 100644
--- a/android/app/src/main/res/xml/timetable_widget_info.xml
+++ b/android/app/src/main/res/xml/timetable_widget_info.xml
@@ -6,8 +6,9 @@
     android:targetCellWidth="2"
     android:targetCellHeight="2"
     android:initialLayout="@layout/timetable_widget"
+    android:initialKeyguardLayout="@layout/timetable_widget_compact_keyguard"
     android:previewLayout="@layout/timetable_widget_preview"
     android:description="@string/widget_description"
     android:updatePeriodMillis="0"
     android:resizeMode="vertical"
-    android:widgetCategory="home_screen" />
+    android:widgetCategory="home_screen|keyguard" />
diff --git a/android/app/src/main/res/xml/timetable_widget_wide_info.xml b/android/app/src/main/res/xml/timetable_widget_wide_info.xml
index c4a6fe0..1284979 100644
--- a/android/app/src/main/res/xml/timetable_widget_wide_info.xml
+++ b/android/app/src/main/res/xml/timetable_widget_wide_info.xml
@@ -10,4 +10,4 @@
     android:description="@string/widget_description"
     android:updatePeriodMillis="0"
     android:resizeMode="vertical"
-    android:widgetCategory="home_screen" />
+    android:widgetCategory="home_screen|keyguard" />