diff -ru gcc-4.9-20150204/gcc/config/i386/mingw32.h gcc/gcc/config/i386/mingw32.h
--- gcc-4.9-20150204/gcc/config/i386/mingw32.h	2014-04-23 11:46:13.000000000 +0200
+++ gcc/gcc/config/i386/mingw32.h	2015-02-09 15:37:33.864238829 +0200
@@ -162,7 +162,7 @@
 /* For native mingw-version we need to take care that NATIVE_SYSTEM_HEADER_DIR
    macro contains POSIX-style path.  See bug 52947.  */
 #undef NATIVE_SYSTEM_HEADER_DIR
-#define NATIVE_SYSTEM_HEADER_DIR "/mingw/include"
+#define NATIVE_SYSTEM_HEADER_DIR "/include"
 
 /* Output STRING, a string representing a filename, to FILE.
    We canonicalize it to be in Unix format (backslashes are replaced
diff -ru gcc-4.9-20150204/gcc/config.gcc gcc/gcc/config.gcc
--- gcc-4.9-20150204/gcc/config.gcc	2014-11-07 18:40:16.000000000 +0200
+++ gcc/gcc/config.gcc	2015-02-09 15:38:07.376239240 +0200
@@ -1666,7 +1666,7 @@
 			tmake_file="${tmake_file} i386/t-mingw-w32"
 			;;
 	esac
-        native_system_header_dir=/mingw/include
+        native_system_header_dir=/include
 	target_gtfiles="\$(srcdir)/config/i386/winnt.c"
 	extra_options="${extra_options} i386/cygming.opt i386/mingw.opt"
 	case ${target} in