diff --git a/NEWS b/NEWS
index 5801b90bd..fb9111ead 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,6 @@
 ver 0.20.4 (not yet released)
 * workaround for GCC 4.9 "constexpr" bug
+* fix FreeBSD build failure
 
 ver 0.20.3 (2017/01/25)
 * protocol
diff --git a/src/util/VarSize.hxx b/src/util/VarSize.hxx
index a386e5dc4..5f383bc4b 100644
--- a/src/util/VarSize.hxx
+++ b/src/util/VarSize.hxx
@@ -36,6 +36,7 @@
 #include <type_traits>
 #include <utility>
 #include <new>
+#include <cstdlib>
 
 /**
  * Allocate and construct a variable-size object.  That is useful for