diff --git a/reactos/w32api/include/ddk/winddk.h b/reactos/w32api/include/ddk/winddk.h
index ce4b615339f..8e82e7c4051 100644
--- a/reactos/w32api/include/ddk/winddk.h
+++ b/reactos/w32api/include/ddk/winddk.h
@@ -3782,9 +3782,6 @@ typedef struct _DRIVER_VERIFIER_THUNK_PAIRS {
 #define RTL_RANGE_LIST_SHARED_OK          0x00000001
 #define RTL_RANGE_LIST_NULL_CONFLICT_OK   0x00000002
 
-#define RTL_RANGE_LIST_SHARED_OK          0x00000001
-#define RTL_RANGE_LIST_NULL_CONFLICT_OK   0x00000002
-
 #define RTL_RANGE_LIST_MERGE_IF_CONFLICT  RTL_RANGE_LIST_ADD_IF_CONFLICT
 
 typedef struct _RTL_RANGE {
@@ -3814,7 +3811,7 @@ typedef struct _RANGE_LIST_ITERATOR {
 } RTL_RANGE_LIST_ITERATOR, *PRTL_RANGE_LIST_ITERATOR;
 
 typedef BOOLEAN
-(*PRTL_CONFLICT_RANGE_CALLBACK)(
+(DDKAPI *PRTL_CONFLICT_RANGE_CALLBACK)(
   IN PVOID  Context,
   IN PRTL_RANGE  Range);