diff --git a/index.ts b/index.ts
index 7e9906b0..2afff2d5 100644
--- a/index.ts
+++ b/index.ts
@@ -552,6 +552,9 @@ export class ModalEditor extends CustomEditor {
   private readonly cursorShapeRuntime: CursorShapeRuntime | null;
   private lastCursorShapeSequence: CursorShapeSequence | null = null;
 
+  private lastLineCacheKey: { line: string; width: number; label: string } = { line: "", width: 0, label: "" };
+  private lastLineCacheResult: string = "";
+
   // Unnamed register
   private unnamedRegister: string = "";
   private clipboardMirrorPolicy: ClipboardMirrorPolicy = DEFAULT_CLIPBOARD_MIRROR_POLICY;
@@ -3021,7 +3024,15 @@ export class ModalEditor extends CustomEditor {
     const last = lines.length - 1;
     const lastLine = lines[last];
     if (lastLine && visibleWidth(lastLine) >= visibleWidth(rawLabel)) {
-      lines[last] = truncateToWidth(lastLine, width - visibleWidth(rawLabel), "") + label;
+      const contentWidth = width - visibleWidth(rawLabel);
+      const k = this.lastLineCacheKey;
+      if (lastLine !== k.line || contentWidth !== k.width || label !== k.label) {
+        k.line = lastLine;
+        k.width = contentWidth;
+        k.label = label;
+        this.lastLineCacheResult = truncateToWidth(lastLine, contentWidth, "") + label;
+      }
+      lines[last] = this.lastLineCacheResult;
     } else {
       lines[last] = label;
     }