diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index d7aca471e..be7896df1 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -2041,13 +2041,10 @@ void cmGlobalGenerator::SetConfiguredFilesPath(cmGlobalGenerator* gen)
     }
 }
 
-bool cmGlobalGenerator::IsExcluded(cmLocalGenerator* root,
-                                   cmLocalGenerator* gen) const
+bool cmGlobalGenerator::IsExcluded(cmState::Snapshot const& rootSnp,
+                       cmState::Snapshot const& snp_) const
 {
-  assert(gen);
-
-  cmState::Snapshot rootSnp = root->GetStateSnapshot();
-  cmState::Snapshot snp = gen->GetStateSnapshot();
+  cmState::Snapshot snp = snp_;
   while (snp.IsValid())
     {
     if(snp == rootSnp)
@@ -2066,6 +2063,17 @@ bool cmGlobalGenerator::IsExcluded(cmLocalGenerator* root,
   return false;
 }
 
+bool cmGlobalGenerator::IsExcluded(cmLocalGenerator* root,
+                                   cmLocalGenerator* gen) const
+{
+  assert(gen);
+
+  cmState::Snapshot rootSnp = root->GetStateSnapshot();
+  cmState::Snapshot snp = gen->GetStateSnapshot();
+
+  return this->IsExcluded(rootSnp, snp);
+}
+
 bool cmGlobalGenerator::IsExcluded(cmLocalGenerator* root,
                                    cmGeneratorTarget* target) const
 {
diff --git a/Source/cmGlobalGenerator.h b/Source/cmGlobalGenerator.h
index fe710f195..23501bc00 100644
--- a/Source/cmGlobalGenerator.h
+++ b/Source/cmGlobalGenerator.h
@@ -396,6 +396,8 @@ protected:
   // has been populated.
   void FillProjectMap();
   void CheckLocalGenerators();
+  bool IsExcluded(cmState::Snapshot const& root,
+                  cmState::Snapshot const& snp) const;
   bool IsExcluded(cmLocalGenerator* root, cmLocalGenerator* gen) const;
   bool IsExcluded(cmLocalGenerator* root, cmGeneratorTarget* target) const;
   virtual void InitializeProgressMarks() {}