diff --git a/Source/cmGeneratorTarget.h b/Source/cmGeneratorTarget.h
index 6aff5f029..8b760f1f5 100644
--- a/Source/cmGeneratorTarget.h
+++ b/Source/cmGeneratorTarget.h
@@ -104,7 +104,7 @@ struct cmStrictTargetComparison {
   bool operator()(cmTarget const* t1, cmTarget const* t2) const;
 };
 
-typedef std::map<cmTarget*,
+typedef std::map<cmTarget const*,
                  cmGeneratorTarget*,
                  cmStrictTargetComparison> cmGeneratorTargetsType;
 
diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index 91a75949e..e4a924621 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -1432,7 +1432,8 @@ void cmGlobalGenerator::ClearGeneratorMembers()
 }
 
 //----------------------------------------------------------------------------
-cmGeneratorTarget* cmGlobalGenerator::GetGeneratorTarget(cmTarget* t) const
+cmGeneratorTarget*
+cmGlobalGenerator::GetGeneratorTarget(cmTarget const* t) const
 {
   cmGeneratorTargetsType::const_iterator ti = this->GeneratorTargets.find(t);
   if(ti == this->GeneratorTargets.end())
diff --git a/Source/cmGlobalGenerator.h b/Source/cmGlobalGenerator.h
index e90af6c8d..b7bc47536 100644
--- a/Source/cmGlobalGenerator.h
+++ b/Source/cmGlobalGenerator.h
@@ -269,7 +269,7 @@ public:
   TargetDependSet const& GetTargetDirectDepends(cmTarget const& target);
 
   /** Get per-target generator information.  */
-  cmGeneratorTarget* GetGeneratorTarget(cmTarget*) const;
+  cmGeneratorTarget* GetGeneratorTarget(cmTarget const*) const;
 
   const std::map<cmStdString, std::vector<cmLocalGenerator*> >& GetProjectMap()
                                                const {return this->ProjectMap;}