diff --git a/Source/cmGraphVizWriter.cxx b/Source/cmGraphVizWriter.cxx
index 94918a5e6..00befec3f 100644
--- a/Source/cmGraphVizWriter.cxx
+++ b/Source/cmGraphVizWriter.cxx
@@ -55,9 +55,8 @@ cmGraphVizWriter::cmGraphVizWriter(const std::vector<cmLocalGenerator*>&
 ,GenerateForSharedLibs(true)
 ,GenerateForModuleLibs(true)
 ,LocalGenerators(localGenerators)
+,HaveTargetsAndLibs(false)
 {
-  int cnt = collectAllTargets();
-  collectAllExternalLibs(cnt);
 }
 
 
@@ -137,6 +136,8 @@ void cmGraphVizWriter::ReadSettings(const char* settingsFileName,
 
 void cmGraphVizWriter::WritePerTargetFiles(const char* fileName)
 {
+  this->CollectTargetsAndLibs();
+
   for(std::map<cmStdString, const cmTarget*>::const_iterator ptrIt =
                                                       this->TargetPtrs.begin();
       ptrIt != this->TargetPtrs.end();
@@ -177,6 +178,8 @@ void cmGraphVizWriter::WritePerTargetFiles(const char* fileName)
 
 void cmGraphVizWriter::WriteGlobalFile(const char* fileName)
 {
+  this->CollectTargetsAndLibs();
+
   cmGeneratedFileStream str(fileName);
   if ( !str )
     {
@@ -295,7 +298,18 @@ void cmGraphVizWriter::WriteNode(const char* targetName,
 }
 
 
-int cmGraphVizWriter::collectAllTargets()
+void cmGraphVizWriter::CollectTargetsAndLibs()
+{
+  if (this->HaveTargetsAndLibs == false)
+    {
+    this->HaveTargetsAndLibs = true;
+    int cnt = this->CollectAllTargets();
+    this->CollectAllExternalLibs(cnt);
+    }
+}
+
+
+int cmGraphVizWriter::CollectAllTargets()
 {
   int cnt = 0;
   // First pass get the list of all cmake targets
@@ -327,7 +341,7 @@ int cmGraphVizWriter::collectAllTargets()
 }
 
 
-int cmGraphVizWriter::collectAllExternalLibs(int cnt)
+int cmGraphVizWriter::CollectAllExternalLibs(int cnt)
 {
   // Ok, now find all the stuff we link to that is not in cmake
   for (std::vector<cmLocalGenerator*>::const_iterator lit =
diff --git a/Source/cmGraphVizWriter.h b/Source/cmGraphVizWriter.h
index c9e5fbdc4..88842a6f0 100644
--- a/Source/cmGraphVizWriter.h
+++ b/Source/cmGraphVizWriter.h
@@ -15,6 +15,7 @@
 #include "cmLocalGenerator.h"
 #include "cmGeneratedFileStream.h"
 #include "cmTarget.h"
+#include <cmsys/RegularExpression.hxx>
 
 
 /** This class implements writing files for graphviz (dot) for graphs
@@ -34,9 +35,11 @@ public:
 
 protected:
 
-  int collectAllTargets();
+  void CollectTargetsAndLibs();
 
-  int collectAllExternalLibs(int cnt);
+  int CollectAllTargets();
+
+  int CollectAllExternalLibs(int cnt);
 
   void WriteHeader(cmGeneratedFileStream& str) const;
 
@@ -65,6 +68,8 @@ protected:
   bool GenerateForSharedLibs;
   bool GenerateForModuleLibs;
 
+  cmsys::RegularExpression TargetIgnoreRegex;
+
   std::set<cmStdString> TargetsToIgnore;
 
   const std::vector<cmLocalGenerator*>& LocalGenerators;
@@ -73,6 +78,7 @@ protected:
   // maps from the actual target names to node names in dot:
   std::map<cmStdString, cmStdString> TargetNamesNodes;
 
+  bool HaveTargetsAndLibs;
 };
 
 #endif