diff --git a/sdk/xtdk/rtlfuncs.h b/sdk/xtdk/rtlfuncs.h
index cbeb95a2..2e16ebaf 100644
--- a/sdk/xtdk/rtlfuncs.h
+++ b/sdk/xtdk/rtlfuncs.h
@@ -61,8 +61,8 @@ RtlClearBit(IN PRTL_BITMAP BitMap,
 XTAPI
 VOID
 RtlClearBits(IN PRTL_BITMAP BitMap,
-             IN ULONG StartingIndex,
-             IN ULONG Length);
+             IN ULONG_PTR StartingIndex,
+             IN ULONG_PTR Length);
 
 XTAPI
 BOOLEAN
@@ -194,8 +194,8 @@ RtlSetBit(IN PRTL_BITMAP BitMap,
 XTAPI
 VOID
 RtlSetBits(IN PRTL_BITMAP BitMap,
-           IN ULONG StartingIndex,
-           IN ULONG Length);
+           IN ULONG_PTR StartingIndex,
+           IN ULONG_PTR Length);
 
 XTAPI
 VOID
diff --git a/xtoskrnl/rtl/bitmap.c b/xtoskrnl/rtl/bitmap.c
index 15d777cc..04e6936b 100644
--- a/xtoskrnl/rtl/bitmap.c
+++ b/xtoskrnl/rtl/bitmap.c
@@ -75,8 +75,8 @@ RtlClearBit(IN PRTL_BITMAP BitMap,
 XTAPI
 VOID
 RtlClearBits(IN PRTL_BITMAP BitMap,
-             IN ULONG StartingIndex,
-             IN ULONG Length)
+             IN ULONG_PTR StartingIndex,
+             IN ULONG_PTR Length)
 {
     ULONG_PTR BitOffset, Mask;
     PULONG_PTR Buffer;
@@ -249,8 +249,8 @@ RtlSetBit(IN PRTL_BITMAP BitMap,
 XTAPI
 VOID
 RtlSetBits(IN PRTL_BITMAP BitMap,
-           IN ULONG StartingIndex,
-           IN ULONG Length)
+           IN ULONG_PTR StartingIndex,
+           IN ULONG_PTR Length)
 {
     ULONG_PTR BitOffset, Mask;
     PULONG_PTR Buffer;