diff --git a/public/res/extensions/scrollLink.js b/public/res/extensions/scrollLink.js
index 39921196..cb9e25b3 100644
--- a/public/res/extensions/scrollLink.js
+++ b/public/res/extensions/scrollLink.js
@@ -106,7 +106,7 @@ define([
                 // Something wrong in the algorithm...
                 return;
             }
-            var posInSection = (srcScrollTop - srcSection.startOffset) / srcSection.height;
+            var posInSection = (srcScrollTop - srcSection.startOffset) / (srcSection.height || 1);
             var destSection = destSectionList[sectionIndex];
             return destSection.startOffset + destSection.height * posInSection;
         }