diff -r 57c23af0b140 -r 93f724176d5e libpurple/protocols/gg/lib/config.h
--- a/libpurple/protocols/gg/lib/config.h	Thu Apr 17 01:31:07 2014 +0200
+++ b/libpurple/protocols/gg/lib/config.h	Thu Apr 17 01:36:13 2014 +0200
@@ -31,7 +31,7 @@
 
 /* Defined if this machine has C99-compiliant vsnprintf(). */
 #undef HAVE_C99_VSNPRINTF
-#ifndef _WIN32
+#if !defined(_WIN32) || (defined(__MINGW64_VERSION_MAJOR) && __MINGW64_VERSION_MAJOR >= 3)
 #  define HAVE_C99_VSNPRINTF
 #endif