diff --git a/include/boost/range/iterator_range.hpp b/include/boost/range/iterator_range.hpp
index 147aeb9..4d33587 100755
--- a/include/boost/range/iterator_range.hpp
+++ b/include/boost/range/iterator_range.hpp
@@ -14,7 +14,8 @@
 #include <boost/range/functions.hpp>
 #include <boost/range/result_iterator.hpp>
 #include <boost/range/difference_type.hpp>
-#include <boost/iterator/iterator_traits.hpp>
+#include <boost/iterator/iterator_traits.hpp>    
+#include <boost/assert.hpp>
 #include <iterator>
 #include <algorithm>
 #include <ostream>
diff --git a/include/boost/range/sub_range.hpp b/include/boost/range/sub_range.hpp
index ce505a5..1bb6581 100755
--- a/include/boost/range/sub_range.hpp
+++ b/include/boost/range/sub_range.hpp
@@ -17,6 +17,7 @@
 #include <boost/range/result_iterator.hpp>
 #include <boost/range/size_type.hpp>
 #include <boost/range/difference_type.hpp>
+#include <boost/assert.hpp>
 
 namespace boost
 {