diff --git a/lib/Analysis/GRExprEngine.cpp b/lib/Analysis/GRExprEngine.cpp
index fc7bd34..4e88f18 100644
--- a/lib/Analysis/GRExprEngine.cpp
+++ b/lib/Analysis/GRExprEngine.cpp
@@ -418,7 +418,7 @@
                             CleanedState, SymReaper);
 
     if (Checkers.empty())
-      Tmp = Tmp2;
+      Tmp.insert(Tmp2);
     else {
       ExplodedNodeSet Tmp3;
       ExplodedNodeSet *SrcSet = &Tmp2;