diff --git a/histogram.cc b/histogram.cc
index 20234a8994501262b464ffb692f5e8d2e3d4e526..e60b626fde1a49250cf598fa3029b367baf07a7f 100644
--- a/histogram.cc
+++ b/histogram.cc
@@ -9,7 +9,6 @@
 #include "miscmaths.h"
 #include "histogram.h"
 
-#include <strstream>
 using namespace std;
 
 #ifndef NO_NAMESPACE