diff --git a/GNUmakefile b/GNUmakefile
index 46ac700..d8bf27c 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -6,7 +6,7 @@ CXX=$(KROSS)g++
 RC=$(KROSS)windres
 
 LINK = $(CXX)
-CFLAGS = -O3 -Iinclude -DUNICODE -D_UNICODE -DWIN32_LEAN_AND_MEAN -DWINVER=0x0501 -D_WIN32_WINNT=0x0501
+CFLAGS = -O3 -Iinclude -DUNICODE -D_UNICODE -DWIN32_LEAN_AND_MEAN -DWINVER=0x0601 -D_WIN32_WINNT=0x0601
 RCFLAGS = -Iinclude
 LDFLAGS = -s -static -static-libstdc++ -mwindows