diff --git a/SimCalorimetry/HcalSimAlgos/src/HcalSiPM.cc b/SimCalorimetry/HcalSimAlgos/src/HcalSiPM.cc
index 7b1fcd82fc1b2..6510b94ecd833 100644
--- a/SimCalorimetry/HcalSimAlgos/src/HcalSiPM.cc
+++ b/SimCalorimetry/HcalSimAlgos/src/HcalSiPM.cc
@@ -5,6 +5,7 @@
 #include "CLHEP/Random/RandFlat.h"
 
 #include <cmath>
+#include <cassert>
 
 using std::vector;
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