diff --git a/content/base/src/nsGenericElement.cpp b/content/base/src/nsGenericElement.cpp
index a4a38900dc3b..fbf2eae6373f 100644
--- a/content/base/src/nsGenericElement.cpp
+++ b/content/base/src/nsGenericElement.cpp
@@ -4112,8 +4112,6 @@ nsGenericElement::GetChildAt(PRUint32 aIndex) const
 PRInt32
 nsGenericElement::IndexOf(nsIContent* aPossibleChild) const
 {
-  NS_PRECONDITION(nsnull != aPossibleChild, "null ptr");
-
   return mAttrsAndChildren.IndexOfChild(aPossibleChild);
 }