diff --git a/rbutil/rbutilqt/rbutilqt.pro b/rbutil/rbutilqt/rbutilqt.pro
index c431c824c7..227cb9601f 100644
--- a/rbutil/rbutilqt/rbutilqt.pro
+++ b/rbutil/rbutilqt/rbutilqt.pro
@@ -130,6 +130,9 @@ DEFINES += RBUTIL _LARGEFILE64_SOURCE
 
 # platform specific
 win32 {
+    # use MinGW's implementation of stdio functions for extended format string
+    # support.
+    DEFINES += __USE_MINGW_ANSI_STDIO=1
     LIBS += -lsetupapi -lnetapi32
 }
 win32:static {
diff --git a/rbutil/sansapatcher/Makefile b/rbutil/sansapatcher/Makefile
index be764c90f4..05739245b9 100644
--- a/rbutil/sansapatcher/Makefile
+++ b/rbutil/sansapatcher/Makefile
@@ -8,6 +8,7 @@ else
 ifeq ($(findstring MINGW,$(shell uname)),MINGW)
 OUTPUT=sansapatcher.exe
 CROSS=
+CFLAGS+=-D__USE_MINGW_ANSI_STDIO=1
 else
 OUTPUT=sansapatcher
 CROSS=i586-mingw32msvc-