diff --git a/reactos/boot/freeldr/freeldr/reactos/binhive.c b/reactos/boot/freeldr/freeldr/reactos/binhive.c
index 8e0e2aec403..ac484ac38bb 100644
--- a/reactos/boot/freeldr/freeldr/reactos/binhive.c
+++ b/reactos/boot/freeldr/freeldr/reactos/binhive.c
@@ -27,7 +27,7 @@
 
 static PVOID
 NTAPI
-CmpAllocate (ULONG Size, BOOLEAN Paged)
+CmpAllocate (SIZE_T Size, BOOLEAN Paged)
 {
   return MmAllocateMemory(Size);
 }
diff --git a/reactos/lib/cmlib/hivecell.c b/reactos/lib/cmlib/hivecell.c
index cc3d5d5203d..b96a793f142 100644
--- a/reactos/lib/cmlib/hivecell.c
+++ b/reactos/lib/cmlib/hivecell.c
@@ -308,7 +308,7 @@ HvpCreateHiveFreeCellList(
 HCELL_INDEX CMAPI
 HvAllocateCell(
    PHHIVE RegistryHive,
-   ULONG Size,
+   SIZE_T Size,
    HV_STORAGE_TYPE Storage)
 {
    PHCELL FreeCell;