diff --git a/src/calibre/gui2/convert/epub_output.ui b/src/calibre/gui2/convert/epub_output.ui
index fa939d289f..e763acb458 100644
--- a/src/calibre/gui2/convert/epub_output.ui
+++ b/src/calibre/gui2/convert/epub_output.ui
@@ -37,7 +37,7 @@
       <string> KB</string>
      </property>
      <property name="minimum">
-      <number>25</number>
+      <number>0</number>
      </property>
      <property name="maximum">
       <number>1000000</number>