diff --git a/win32/libssh2_config.h b/win32/libssh2_config.h
index 0fb867b8..c5d04858 100644
--- a/win32/libssh2_config.h
+++ b/win32/libssh2_config.h
@@ -43,6 +43,7 @@ static inline int usleep(int udelay)
 }
 
 #define snprintf _snprintf
+#define vsnprintf _vsnprintf
 
 /* Compile in zlib support */
 #define LIBSSH2_HAVE_ZLIB 1