diff --git a/include/ddk/ntddk.h b/include/ddk/ntddk.h
index b9f8295db88..497d42da39f 100644
--- a/include/ddk/ntddk.h
+++ b/include/ddk/ntddk.h
@@ -165,7 +165,7 @@ typedef enum _RTL_GENERIC_COMPARE_RESULTS {
 
 typedef RTL_GENERIC_COMPARE_RESULTS (WINAPI *PRTL_AVL_COMPARE_ROUTINE)(struct _RTL_AVL_TABLE *, void *, void *);
 
-typedef void (WINAPI *PRTL_AVL_ALLOCATE_ROUTINE)(struct _RTL_AVL_TABLE *, LONG);
+typedef void * (WINAPI *PRTL_AVL_ALLOCATE_ROUTINE)(struct _RTL_AVL_TABLE *, LONG);
 
 typedef void (WINAPI *PRTL_AVL_FREE_ROUTINE )(struct _RTL_AVL_TABLE *, void *buffer);