diff --git a/include/winbase.h b/include/winbase.h
index 6381850..398b18f 100644
--- a/include/winbase.h
+++ b/include/winbase.h
@@ -602,6 +602,8 @@
 #define IDLE_PRIORITY_CLASS         0x00000040
 #define HIGH_PRIORITY_CLASS         0x00000080
 #define REALTIME_PRIORITY_CLASS     0x00000100
+#define BELOW_NORMAL_PRIORITY_CLASS 0x00004000
+#define ABOVE_NORMAL_PRIORITY_CLASS 0x00008000
 #define CREATE_NEW_PROCESS_GROUP    0x00000200
 #define CREATE_UNICODE_ENVIRONMENT  0x00000400
 #define CREATE_SEPARATE_WOW_VDM     0x00000800