diff --git a/app/src/main/java/com/ganjoor/android/ui/PoemScreen.kt b/app/src/main/java/com/ganjoor/android/ui/PoemScreen.kt
index 0b11f80..203e1d4 100644
--- a/app/src/main/java/com/ganjoor/android/ui/PoemScreen.kt
+++ b/app/src/main/java/com/ganjoor/android/ui/PoemScreen.kt
@@ -111,7 +111,7 @@ fun PoemScreen(
     // foldable held open in portrait the page is already down to ~450dp, and a panel beside it
     // left the verse a couple of characters a line. Where it does not fit, the sheet is the
     // better answer: it covers the foot of the poem but leaves the lines whole.
-    val roomForPanel = wide && maxWidth - DictionaryPanelWidth >= MinPageMeasure
+    val roomForPanel = dictionaryFitsBeside(maxWidth, wide)
 
     Load(
         key = fullUrl,
diff --git a/app/src/main/java/com/ganjoor/android/ui/WordSheet.kt b/app/src/main/java/com/ganjoor/android/ui/WordSheet.kt
index 27e8f53..22bdf6d 100644
--- a/app/src/main/java/com/ganjoor/android/ui/WordSheet.kt
+++ b/app/src/main/java/com/ganjoor/android/ui/WordSheet.kt
@@ -39,6 +39,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalLayoutDirection
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.LayoutDirection
+import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
 import com.ganjoor.android.R
 import com.ganjoor.android.data.Definition
@@ -64,6 +65,21 @@ val DictionaryPanelWidth = 216.dp
  */
 val MinPageMeasure = 400.dp
 
+/**
+ * Whether the dictionary earns a column of its own beside a page [pageWidth] wide.
+ *
+ * Not a question about the window but about the page: by the time a poem is open the columns have
+ * already taken their room, and on a book-style foldable held open in portrait what is left is
+ * about 450dp. A panel beside that leaves the verse a couple of characters a line, so below
+ * [MinPageMeasure] the bottom sheet is used instead — it covers the foot of the poem but leaves
+ * every line whole.
+ *
+ * A pure function so the rule can be tested: the gesture that reaches it cannot be driven
+ * reliably, but the arithmetic behind it can.
+ */
+internal fun dictionaryFitsBeside(pageWidth: Dp, wide: Boolean): Boolean =
+    wide && pageWidth - DictionaryPanelWidth >= MinPageMeasure
+
 /** English prose inside an otherwise right-to-left sheet. */
 @Composable
 private fun LeftToRight(content: @Composable () -> Unit) {
diff --git a/app/src/test/java/com/ganjoor/android/DictionaryPanelFitTest.kt b/app/src/test/java/com/ganjoor/android/DictionaryPanelFitTest.kt
new file mode 100644
index 0000000..d0c18b0
--- /dev/null
+++ b/app/src/test/java/com/ganjoor/android/DictionaryPanelFitTest.kt
@@ -0,0 +1,41 @@
+package com.ganjoor.android
+
+import androidx.compose.ui.unit.dp
+import com.ganjoor.android.ui.dictionaryFitsBeside
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * The rule that decides whether the dictionary opens beside the poem or as a sheet over it.
+ *
+ * Driving the gesture that reaches it — a tap landing on the glyphs of one Persian word — is not
+ * something adb does reliably, so the arithmetic is tested directly instead.
+ */
+class DictionaryPanelFitTest {
+
+    @Test
+    fun `a tablet has room beside the poem`() {
+        // 1280dp window, less the poets rail and two list columns, leaves the page about 900dp.
+        assertTrue(dictionaryFitsBeside(900.dp, wide = true))
+    }
+
+    @Test
+    fun `a foldable open in portrait does not`() {
+        // 700dp window, less the rail and the newest column, leaves about 450dp — and 450 less
+        // the 216dp panel is 234dp, which is a cramped phone column, not a measure for a verse.
+        assertFalse(dictionaryFitsBeside(450.dp, wide = true))
+    }
+
+    @Test
+    fun `a phone never gets the panel, however the page is measured`() {
+        assertFalse(dictionaryFitsBeside(420.dp, wide = false))
+        assertFalse(dictionaryFitsBeside(2000.dp, wide = false))
+    }
+
+    @Test
+    fun `the boundary is the panel plus the minimum measure`() {
+        assertTrue(dictionaryFitsBeside(616.dp, wide = true))   // 400 + 216, exactly
+        assertFalse(dictionaryFitsBeside(615.dp, wide = true))
+    }
+}