diff --git a/src/calibre/gui2/convert/epub_output.ui b/src/calibre/gui2/convert/epub_output.ui
index a0d9570226..606ed62065 100644
--- a/src/calibre/gui2/convert/epub_output.ui
+++ b/src/calibre/gui2/convert/epub_output.ui
@@ -58,7 +58,7 @@
KB
- 100
+ 25
1000000