diff --git a/lib/Analysis/DataStructure/DataStructure.cpp b/lib/Analysis/DataStructure/DataStructure.cpp
index 9cf77ae..9d9813c 100644
--- a/lib/Analysis/DataStructure/DataStructure.cpp
+++ b/lib/Analysis/DataStructure/DataStructure.cpp
@@ -1409,7 +1409,7 @@
 // inlining graphs.
 //
 void DSGraph::removeDeadNodes(unsigned Flags) {
-  DEBUG(AssertGraphOK(); GlobalsGraph->AssertGraphOK());
+  DEBUG(AssertGraphOK(); if (GlobalsGraph) GlobalsGraph->AssertGraphOK());
 
   // Reduce the amount of work we have to do... remove dummy nodes left over by
   // merging...