diff --git a/packages/runtime/src/host/text-measure.ts b/packages/runtime/src/host/text-measure.ts
index 714fe57..8cd34f5 100644
--- a/packages/runtime/src/host/text-measure.ts
+++ b/packages/runtime/src/host/text-measure.ts
@@ -37,13 +37,14 @@ export type WrapMode = NonNullable<TextProps["wrap"]>;
  * `slice-ansi` can overshoot when a wide character straddles the boundary, so
  * we reduce the slice position until the result fits.
  */
-function safeSliceEnd(text: string, maxCols: number): string {
+export function safeSliceEnd(text: string, maxCols: number): string {
   if (maxCols <= 0) return "";
-  let sliced = sliceAnsi(text, 0, maxCols);
+  let end = maxCols;
+  let sliced = sliceAnsi(text, 0, end);
   let w = stringWidth(sliced);
-  while (w > maxCols && maxCols > 0) {
-    maxCols--;
-    sliced = sliceAnsi(text, 0, maxCols);
+  while (w > maxCols && end > 0) {
+    end--;
+    sliced = sliceAnsi(text, 0, end);
     w = stringWidth(sliced);
   }
   return sliced;
diff --git a/packages/runtime/src/paint/paint.ts b/packages/runtime/src/paint/paint.ts
index fddf53e..1c65d28 100644
--- a/packages/runtime/src/paint/paint.ts
+++ b/packages/runtime/src/paint/paint.ts
@@ -19,7 +19,7 @@ import type {
   BoxProps,
 } from "../host/nodes.ts";
 import { createRoot as createIsoRoot } from "../host/nodes.ts";
-import { wrapText } from "../host/text-measure.ts";
+import { wrapText, safeSliceEnd } from "../host/text-measure.ts";
 import {
   attachYoga,
   detachYoga,
@@ -29,19 +29,6 @@ import {
 
 export type Transformer = (line: string, lineIndex: number) => string;
 
-function safeSliceEnd(text: string, maxCols: number): string {
-  if (maxCols <= 0) return "";
-  let end = maxCols;
-  let sliced = sliceAnsi(text, 0, end);
-  let w = stringWidth(sliced);
-  while (w > maxCols && end > 0) {
-    end--;
-    sliced = sliceAnsi(text, 0, end);
-    w = stringWidth(sliced);
-  }
-  return sliced;
-}
-
 interface ClipRect {
   x1: number | undefined;
   x2: number | undefined;