diff --git a/include/boost/random/detail/large_arithmetic.hpp b/include/boost/random/detail/large_arithmetic.hpp
index 3f96e07..66f6b4e 100644
--- a/include/boost/random/detail/large_arithmetic.hpp
+++ b/include/boost/random/detail/large_arithmetic.hpp
@@ -96,8 +96,8 @@ inline div_t muldivmod(boost::uintmax_t a, boost::uintmax_t b, boost::uintmax_t
 
         quotient[i - 2] = q;
         product[i] = 0;
-        product[i-1] = (rem >> bits) & mask;
-        product[i-2] = rem & mask;
+        product[i-1] = static_cast<digit_t>((rem >> bits) & mask);
+        product[i-2] = static_cast<digit_t>(rem & mask);
     }
 
     div_t result = {