diff --git a/Source/cmDefinitions.cxx b/Source/cmDefinitions.cxx
index 873a7b4ec..d1fbe7446 100644
--- a/Source/cmDefinitions.cxx
+++ b/Source/cmDefinitions.cxx
@@ -75,18 +75,13 @@ std::vector<std::string> cmDefinitions::LocalKeys() const
 }
 
 //----------------------------------------------------------------------------
-cmDefinitions cmDefinitions::MakeClosure() const
+cmDefinitions cmDefinitions::MakeClosure(
+    std::list<cmDefinitions const*>::iterator begin,
+    std::list<cmDefinitions const*>::iterator end)
 {
   std::set<std::string> undefined;
   cmDefinitions closure;
-  cmDefinitions const* defs = this;
-  std::list<cmDefinitions const*> ups;
-  while(defs)
-    {
-    ups.push_back(defs);
-    defs = defs->Up;
-    }
-  closure.MakeClosure(undefined, ups.begin(), ups.end());
+  closure.MakeClosure(undefined, begin, end);
   return closure;
 }
 
diff --git a/Source/cmDefinitions.h b/Source/cmDefinitions.h
index 40e053198..67b617069 100644
--- a/Source/cmDefinitions.h
+++ b/Source/cmDefinitions.h
@@ -50,7 +50,9 @@ public:
   /** Compute the set of all defined keys.  */
   std::vector<std::string> ClosureKeys() const;
 
-  cmDefinitions MakeClosure() const;
+  static cmDefinitions MakeClosure(
+      std::list<cmDefinitions const*>::iterator begin,
+      std::list<cmDefinitions const*>::iterator end);
 
 private:
   // String with existence boolean.
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index 8cfb83a57..879709073 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -63,7 +63,15 @@ public:
 
   void InitializeDefinitions(cmMakefile* parent)
   {
-    this->VarStack.back() = parent->Internal->VarStack.back().MakeClosure();
+    std::list<cmDefinitions const*> defPtrs;
+    for (std::list<cmDefinitions>::iterator it =
+         parent->Internal->VarStack.begin();
+         it != parent->Internal->VarStack.end(); ++it)
+      {
+      defPtrs.push_back(&*it);
+      }
+    this->VarStack.back() = cmDefinitions::MakeClosure(defPtrs.begin(),
+                                                       defPtrs.end());
   }
 
   const char* GetDefinition(std::string const& name)