diff --git a/Alignment/OfflineValidation/macros/loopAndPlot.C b/Alignment/OfflineValidation/macros/loopAndPlot.C
index 9052ae3a41097..e75ecb8e903c5 100644
--- a/Alignment/OfflineValidation/macros/loopAndPlot.C
+++ b/Alignment/OfflineValidation/macros/loopAndPlot.C
@@ -4,6 +4,7 @@
 #include "TDirectory.h"
 #include "TFile.h"
 #include "TGaxis.h"
+#include "TGraph.h"
 #include "TH1.h"
 #include "TH2.h"
 #include "TKey.h"