diff --git a/reactos/lib/rtl/heap.c b/reactos/lib/rtl/heap.c
index a19ebca4a20..d3b0efce6d4 100644
--- a/reactos/lib/rtl/heap.c
+++ b/reactos/lib/rtl/heap.c
@@ -1982,9 +1982,9 @@ RtlQueryHeapInformation(HANDLE HeapHandle,
 NTSTATUS
 NTAPI
 RtlMultipleAllocateHeap(IN PVOID HeapHandle,
-                        IN DWORD Flags,
+                        IN ULONG Flags,
                         IN SIZE_T Size,
-                        IN DWORD Count,
+                        IN ULONG Count,
                         OUT PVOID *Array)
 {
     UNIMPLEMENTED;
@@ -1994,8 +1994,8 @@ RtlMultipleAllocateHeap(IN PVOID HeapHandle,
 NTSTATUS
 NTAPI
 RtlMultipleFreeHeap(IN PVOID HeapHandle,
-                    IN DWORD Flags,
-                    IN DWORD Count,
+                    IN ULONG Flags,
+                    IN ULONG Count,
                     OUT PVOID *Array)
 {
     UNIMPLEMENTED;
diff --git a/reactos/lib/rtl/heap_rewrite.c b/reactos/lib/rtl/heap_rewrite.c
index 572e2d9c350..4b6e5b36a82 100644
--- a/reactos/lib/rtl/heap_rewrite.c
+++ b/reactos/lib/rtl/heap_rewrite.c
@@ -3553,9 +3553,9 @@ RtlQueryHeapInformation(HANDLE HeapHandle,
 NTSTATUS
 NTAPI
 RtlMultipleAllocateHeap(IN PVOID HeapHandle,
-                        IN DWORD Flags,
+                        IN ULONG Flags,
                         IN SIZE_T Size,
-                        IN DWORD Count,
+                        IN ULONG Count,
                         OUT PVOID *Array)
 {
     UNIMPLEMENTED;
@@ -3565,8 +3565,8 @@ RtlMultipleAllocateHeap(IN PVOID HeapHandle,
 NTSTATUS
 NTAPI
 RtlMultipleFreeHeap(IN PVOID HeapHandle,
-                    IN DWORD Flags,
-                    IN DWORD Count,
+                    IN ULONG Flags,
+                    IN ULONG Count,
                     OUT PVOID *Array)
 {
     UNIMPLEMENTED;