1 files changed, 4 insertions, 1 deletions
diff --git a/Source/WebCore/rendering/mathml/RenderMathMLRoot.cpp b/Source/WebCore/rendering/mathml/RenderMathMLRoot.cpp
index 075f6ba..51046f8 100644
--- a/Source/WebCore/rendering/mathml/RenderMathMLRoot.cpp
+++ b/Source/WebCore/rendering/mathml/RenderMathMLRoot.cpp
@@ -229,7 +229,10 @@ void RenderMathMLRoot::layout()
     }
     
     // Positioning of the index
-    RenderBoxModelObject* indexBox = toRenderBoxModelObject(firstChild()->firstChild());
+    RenderObject* possibleIndex = firstChild()->firstChild();
+    while (possibleIndex && !possibleIndex->isBoxModelObject())
+        possibleIndex = possibleIndex->nextSibling();
+    RenderBoxModelObject* indexBox = toRenderBoxModelObject(possibleIndex);
     if (!indexBox)
         return;