diff --git a/core/src/primitive/text.rs b/core/src/primitive/text.rs
index 8281225..941f123 100644
--- a/core/src/primitive/text.rs
+++ b/core/src/primitive/text.rs
@@ -106,6 +106,13 @@ impl Default for TextAttrs {
     }
 }
 
+/// How far below the longest line a width may fall and still be answered by
+/// the break in hand. A parent that offers a child the length it reported
+/// composes that length back through the box chain, so the two differ in the
+/// last bits -- and at exactly the longest line, that decides whether a line
+/// fits. Sub-pixel, so no break it admits is one a reader could see.
+const BREAK_EPSILON_PX: f32 = 0.05;
+
 /// Keeps text and its corresponding layout from getting out of sync.
 pub struct TextBuffer {
     text: String,
@@ -189,6 +196,23 @@ impl TextBuffer {
             diag::bump(Counter::TextShapeHits);
             return;
         }
+        // A greedy break at one width is the same break at every width down
+        // to the longest line it produced: each line still fits, and none can
+        // take a word that would not fit in the wider box. So the layout in
+        // hand already answers, and re-breaking would only be a chance to
+        // disagree with itself -- which is what happens when a parent offers
+        // a child the length that child just reported, and the two land
+        // either side of a float.
+        if let Some(key) = &self.layout_key
+            && key.attrs == *attrs
+            && let (Some(broke_at), Some(want)) = (key.max_width, width)
+            && want <= broke_at
+            && want + BREAK_EPSILON_PX >= self.layout.width()
+        {
+            #[cfg(feature = "layout-diagnostics")]
+            diag::bump(Counter::TextShapeHits);
+            return;
+        }
         let same_shaping = self
             .layout_key
             .as_ref()