diff --git a/Lib/fontTools/ttLib/removeOverlaps.py b/Lib/fontTools/ttLib/removeOverlaps.py
index 4ab8a1a64..6dadf4aa5 100644
--- a/Lib/fontTools/ttLib/removeOverlaps.py
+++ b/Lib/fontTools/ttLib/removeOverlaps.py
@@ -87,7 +87,10 @@ def ttfGlyphFromSkPath(path: pathops.Path) -> _g_l_y_f.Glyph:
 def _charString_from_SkPath(
     path: pathops.Path, charString: T2CharString
 ) -> T2CharString:
-    width = charString.width - charString.private.nominalWidthX
+    if charString.width == charString.private.defaultWidthX:
+        width = None
+    else:
+        width = charString.width - charString.private.nominalWidthX
     t2Pen = T2CharStringPen(width=width, glyphSet=None)
     path.draw(t2Pen)
     return t2Pen.getCharString(charString.private, charString.globalSubrs)