diff --git a/src/html/m_layout.cpp b/src/html/m_layout.cpp
index 07b483b7d0..f8f5c34931 100644
--- a/src/html/m_layout.cpp
+++ b/src/html/m_layout.cpp
@@ -406,7 +406,8 @@ TAG_HANDLER_BEGIN(SUBSUP, "SUB,SUP")
         wxHtmlCell *c = cont->GetLastChild();
 
         m_WParser->SetScriptMode(issub ? wxHTML_SCRIPT_SUB : wxHTML_SCRIPT_SUP);
-        m_WParser->SetScriptBaseline(oldbase + c->GetScriptBaseline());
+        m_WParser->SetScriptBaseline(
+                oldbase + c ? c->GetScriptBaseline() : 0);
 
         // select smaller font
         m_WParser->SetFontSize(m_WParser->GetFontSize()-2);