diff --git a/llvm/lib/Analysis/DataStructure/Local.cpp b/llvm/lib/Analysis/DataStructure/Local.cpp
index b497c38..473fb63 100644
--- a/llvm/lib/Analysis/DataStructure/Local.cpp
+++ b/llvm/lib/Analysis/DataStructure/Local.cpp
@@ -246,6 +246,9 @@
     } else if (ConstantIntegral *CI = dyn_cast<ConstantIntegral>(C)) {
       // Random constants are unknown mem
       return NH = createNode()->setUnknownNodeMarker();
+    } else if (isa<UndefValue>(C)) {
+      ScalarMap.erase(V);
+      return 0;
     } else {
       assert(0 && "Unknown constant type!");
     }