diff --git a/include/libtorrent/assert.hpp b/include/libtorrent/assert.hpp
index 5c57e1d23..6577acc46 100644
--- a/include/libtorrent/assert.hpp
+++ b/include/libtorrent/assert.hpp
@@ -38,7 +38,9 @@ POSSIBILITY OF SUCH DAMAGE.
 #undef assert
 #endif
 
-void assert_fail(const char* expr, int line, char const* file, char const* function);
+#include "libtorrent/config.hpp"
+
+TORRENT_EXPORT void assert_fail(const char* expr, int line, char const* file, char const* function);
 
 #define assert(x) if (x) {} else assert_fail(#x, __LINE__, __FILE__, __PRETTY_FUNCTION__)
 
diff --git a/include/libtorrent/config.hpp b/include/libtorrent/config.hpp
index 1281ab84c..b36d4da22 100755
--- a/include/libtorrent/config.hpp
+++ b/include/libtorrent/config.hpp
@@ -34,7 +34,6 @@ POSSIBILITY OF SUCH DAMAGE.
 #define TORRENT_CONFIG_HPP_INCLUDED
 
 #include <boost/config.hpp>
-#include "libtorrent/assert.hpp"
 
 #if defined(__GNUC__) && __GNUC__ >= 4