diff -NBaur vanilla/src/main/include/log4cxx/helpers/thread.h mingw_cross/src/main/include/log4cxx/helpers/thread.h
--- vanilla/src/main/include/log4cxx/helpers/thread.h	2008-04-01 07:34:26.000000000 +0900
+++ mingw_cross/src/main/include/log4cxx/helpers/thread.h	2011-05-09 11:08:23.123558232 +0900
@@ -23,9 +23,13 @@
 
 #if !defined(LOG4CXX_THREAD_FUNC)
 #if defined(_WIN32)
-#define LOG4CXX_THREAD_FUNC __stdcall
+  #if defined(__MINGW32__)
+    #define LOG4CXX_THREAD_FUNC
+  #else
+    #define LOG4CXX_THREAD_FUNC __stdcall
+  #endif
 #else
-#define LOG4CXX_THREAD_FUNC
+  #define LOG4CXX_THREAD_FUNC
 #endif
 #endif