diff --git a/Sources/Generator/Content/Element.swift b/Sources/Generator/Content/Element.swift
index 7c35a36..e3702cb 100644
--- a/Sources/Generator/Content/Element.swift
+++ b/Sources/Generator/Content/Element.swift
@@ -431,7 +431,7 @@ extension Element {
 
         // Find the common elements of the path, which can be discarded
         var index = 0
-        while pageParts[index] == ownParts[index] {
+        while index < pageParts.count && index < ownParts.count && pageParts[index] == ownParts[index] {
             index += 1
         }
         // The relative path needs to go down to the first common folder,