diff --git a/reactos/drivers/bus/serenum/detect.c b/reactos/drivers/bus/serenum/detect.c
index 5cf8cc033d5..655f48b51be 100644
--- a/reactos/drivers/bus/serenum/detect.c
+++ b/reactos/drivers/bus/serenum/detect.c
@@ -17,9 +17,9 @@ DeviceIoControl(
 	IN PDEVICE_OBJECT DeviceObject,
 	IN ULONG CtlCode,
 	IN PVOID InputBuffer OPTIONAL,
-	IN ULONG InputBufferSize,
+	IN ULONG_PTR InputBufferSize,
 	IN OUT PVOID OutputBuffer OPTIONAL,
-	IN OUT PULONG OutputBufferSize)
+	IN OUT PULONG_PTR OutputBufferSize)
 {
 	KEVENT Event;
 	PIRP Irp;
@@ -103,7 +103,7 @@ ReadBytes(
 	IN PDEVICE_OBJECT LowerDevice,
 	OUT PUCHAR Buffer,
 	IN ULONG BufferSize,
-	OUT PULONG FilledBytes)
+	OUT PULONG_PTR FilledBytes)
 {
 	PIRP Irp;
 	IO_STATUS_BLOCK ioStatus;
@@ -258,8 +258,8 @@ SerenumDetectPnpDevice(
 {
 	UCHAR Buffer[256];
 	ULONG BaudRate;
-	ULONG TotalBytesReceived = 0;
-	ULONG Size;
+	ULONG_PTR TotalBytesReceived = 0;
+	ULONG_PTR Size;
 	ULONG Msr, Purge;
 	ULONG i;
 	BOOLEAN BufferContainsBeginId = FALSE;
diff --git a/reactos/drivers/bus/serenum/fdo.c b/reactos/drivers/bus/serenum/fdo.c
index 302a2237f9e..d9c93744055 100644
--- a/reactos/drivers/bus/serenum/fdo.c
+++ b/reactos/drivers/bus/serenum/fdo.c
@@ -10,7 +10,7 @@
 #define NDEBUG
 #include "serenum.h"
 
-NTSTATUS STDCALL
+NTSTATUS NTAPI
 SerenumAddDevice(
 	IN PDRIVER_OBJECT DriverObject,
 	IN PDEVICE_OBJECT Pdo)
@@ -68,7 +68,7 @@ SerenumAddDevice(
 	return STATUS_SUCCESS;
 }
 
-static NTSTATUS STDCALL
+static NTSTATUS NTAPI
 SerenumFdoStartDevice(
 	IN PDEVICE_OBJECT DeviceObject,
 	IN PIRP Irp)
diff --git a/reactos/drivers/bus/serenum/misc.c b/reactos/drivers/bus/serenum/misc.c
index d16ab02f994..bd1575118b6 100644
--- a/reactos/drivers/bus/serenum/misc.c
+++ b/reactos/drivers/bus/serenum/misc.c
@@ -86,7 +86,7 @@ SerenumInitMultiSzString(
 	return Status;
 }
 
-static NTSTATUS STDCALL
+static NTSTATUS NTAPI
 ForwardIrpAndWaitCompletion(
 	IN PDEVICE_OBJECT DeviceObject,
 	IN PIRP Irp,
@@ -128,7 +128,7 @@ ForwardIrpAndWait(
 	return Status;
 }
 
-NTSTATUS STDCALL
+NTSTATUS NTAPI
 ForwardIrpToLowerDeviceAndForget(
 	IN PDEVICE_OBJECT DeviceObject,
 	IN PIRP Irp)
@@ -147,7 +147,7 @@ ForwardIrpToLowerDeviceAndForget(
 	return IoCallDriver(LowerDevice, Irp);
 }
 
-NTSTATUS STDCALL
+NTSTATUS NTAPI
 ForwardIrpToAttachedFdoAndForget(
 	IN PDEVICE_OBJECT DeviceObject,
 	IN PIRP Irp)
@@ -166,7 +166,7 @@ ForwardIrpToAttachedFdoAndForget(
 	return IoCallDriver(Fdo, Irp);
 }
 
-NTSTATUS STDCALL
+NTSTATUS NTAPI
 ForwardIrpAndForget(
 	IN PDEVICE_OBJECT DeviceObject,
 	IN PIRP Irp)
diff --git a/reactos/drivers/bus/serenum/serenum.c b/reactos/drivers/bus/serenum/serenum.c
index b6ee195a35c..f10caab5734 100644
--- a/reactos/drivers/bus/serenum/serenum.c
+++ b/reactos/drivers/bus/serenum/serenum.c
@@ -11,7 +11,7 @@
 #define INITGUID
 #include "serenum.h"
 
-static NTSTATUS STDCALL
+static NTSTATUS NTAPI
 SerenumPnp(
 	IN PDEVICE_OBJECT DeviceObject,
 	IN PIRP Irp)
@@ -22,13 +22,13 @@ SerenumPnp(
 		return SerenumPdoPnp(DeviceObject, Irp);
 }
 
-static VOID STDCALL
+static VOID NTAPI
 DriverUnload(IN PDRIVER_OBJECT DriverObject)
 {
 	// nothing to do here yet
 }
 
-static NTSTATUS STDCALL
+static NTSTATUS NTAPI
 IrpStub(
 	IN PDEVICE_OBJECT DeviceObject,
 	IN PIRP Irp)
@@ -90,7 +90,7 @@ IrpStub(
 /*
  * Standard DriverEntry method.
  */
-NTSTATUS STDCALL
+NTSTATUS NTAPI
 DriverEntry(
 	IN PDRIVER_OBJECT DriverObject,
 	IN PUNICODE_STRING RegPath)
diff --git a/reactos/drivers/bus/serenum/serenum.h b/reactos/drivers/bus/serenum/serenum.h
index aac977f7f72..e65a6a2de18 100644
--- a/reactos/drivers/bus/serenum/serenum.h
+++ b/reactos/drivers/bus/serenum/serenum.h
@@ -15,8 +15,6 @@
 #if defined(__GNUC__)
   #include <debug.h>
 #elif defined(_MSC_VER)
-  #define STDCALL
-
   #define DPRINT1 DbgPrint("(%s:%d) ", __FILE__, __LINE__), DbgPrint
   #define CHECKPOINT1 DbgPrint("(%s:%d)\n", __FILE__, __LINE__)
   #define DPRINT DPRINT1
@@ -88,7 +86,7 @@ SerenumDetectLegacyDevice(
 
 /************************************ fdo.c */
 
-NTSTATUS STDCALL
+NTSTATUS NTAPI
 SerenumAddDevice(
 	IN PDRIVER_OBJECT DriverObject,
 	IN PDEVICE_OBJECT Pdo);
@@ -110,17 +108,17 @@ ForwardIrpAndWait(
 	IN PDEVICE_OBJECT DeviceObject,
 	IN PIRP Irp);
 
-NTSTATUS STDCALL
+NTSTATUS NTAPI
 ForwardIrpToLowerDeviceAndForget(
 	IN PDEVICE_OBJECT DeviceObject,
 	IN PIRP Irp);
 
-NTSTATUS STDCALL
+NTSTATUS NTAPI
 ForwardIrpToAttachedFdoAndForget(
 	IN PDEVICE_OBJECT DeviceObject,
 	IN PIRP Irp);
 
-NTSTATUS STDCALL
+NTSTATUS NTAPI
 ForwardIrpAndForget(
 	IN PDEVICE_OBJECT DeviceObject,
 	IN PIRP Irp);
@@ -134,7 +132,7 @@ SerenumPdoPnp(
 
 /************************************ serenum.c */
 
-NTSTATUS STDCALL
+NTSTATUS NTAPI
 DriverEntry(
 	IN PDRIVER_OBJECT DriverObject,
 	IN PUNICODE_STRING RegPath);