diff --git a/winpr/libwinpr/comm/comm.c b/winpr/libwinpr/comm/comm.c
index 97af7936f..f8e30e793 100644
--- a/winpr/libwinpr/comm/comm.c
+++ b/winpr/libwinpr/comm/comm.c
@@ -70,8 +70,6 @@ typedef struct comm_device COMM_DEVICE;
 static COMM_DEVICE** sCommDevices = NULL;
 static CRITICAL_SECTION sCommDevicesLock;
 
-static HANDLE_CREATOR sCommHandleCreator = { 0 };
-
 static pthread_once_t sCommInitialized = PTHREAD_ONCE_INIT;
 
 static int CommGetFd(HANDLE handle)
diff --git a/winpr/libwinpr/comm/comm_sercx2_sys.c b/winpr/libwinpr/comm/comm_sercx2_sys.c
index 983cb5e39..5cb19f237 100644
--- a/winpr/libwinpr/comm/comm_sercx2_sys.c
+++ b/winpr/libwinpr/comm/comm_sercx2_sys.c
@@ -70,14 +70,13 @@ static const ULONG SERCX2_SYS_SUPPORTED_EV_MASK =
 /* use Serial.sys for basis (not SerCx.sys) */
 static BOOL set_wait_mask(WINPR_COMM* pComm, const ULONG* pWaitMask)
 {
-	ULONG possibleMask = 0;
-	SERIAL_DRIVER* pSerialSys = SerialSys_s();
+	const SERIAL_DRIVER* pSerialSys = SerialSys_s();
 
 	WINPR_ASSERT(pComm);
 	WINPR_ASSERT(pWaitMask);
 	WINPR_ASSERT(pSerialSys);
 
-	possibleMask = *pWaitMask & SERCX2_SYS_SUPPORTED_EV_MASK;
+	const ULONG possibleMask = *pWaitMask & SERCX2_SYS_SUPPORTED_EV_MASK;
 
 	if (possibleMask != *pWaitMask)
 	{
@@ -97,7 +96,7 @@ static BOOL set_wait_mask(WINPR_COMM* pComm, const ULONG* pWaitMask)
 
 static BOOL purge(WINPR_COMM* pComm, const ULONG* pPurgeMask)
 {
-	SERIAL_DRIVER* pSerialSys = SerialSys_s();
+	const SERIAL_DRIVER* pSerialSys = SerialSys_s();
 
 	WINPR_ASSERT(pComm);
 	WINPR_ASSERT(pPurgeMask);
diff --git a/winpr/libwinpr/comm/comm_sercx_sys.c b/winpr/libwinpr/comm/comm_sercx_sys.c
index 7b345d659..39843c1b3 100644
--- a/winpr/libwinpr/comm/comm_sercx_sys.c
+++ b/winpr/libwinpr/comm/comm_sercx_sys.c
@@ -32,7 +32,7 @@ static BOOL set_handflow(WINPR_COMM* pComm, const SERIAL_HANDFLOW* pHandflow)
 {
 	SERIAL_HANDFLOW SerCxHandflow;
 	BOOL result = TRUE;
-	SERIAL_DRIVER* pSerialSys = SerialSys_s();
+	const SERIAL_DRIVER* pSerialSys = SerialSys_s();
 
 	memcpy(&SerCxHandflow, pHandflow, sizeof(SERIAL_HANDFLOW));
 
@@ -121,10 +121,9 @@ static BOOL set_handflow(WINPR_COMM* pComm, const SERIAL_HANDFLOW* pHandflow)
 
 static BOOL get_handflow(WINPR_COMM* pComm, SERIAL_HANDFLOW* pHandflow)
 {
-	BOOL result = 0;
-	SERIAL_DRIVER* pSerialSys = SerialSys_s();
+	const SERIAL_DRIVER* pSerialSys = SerialSys_s();
 
-	result = pSerialSys->get_handflow(pComm, pHandflow);
+	BOOL result = pSerialSys->get_handflow(pComm, pHandflow);
 
 	/* filter out unsupported bits by SerCx.sys
 	 *
@@ -153,10 +152,10 @@ static const ULONG SERCX_SYS_SUPPORTED_EV_MASK = SERIAL_EV_RXCHAR |
 
 static BOOL set_wait_mask(WINPR_COMM* pComm, const ULONG* pWaitMask)
 {
-	ULONG possibleMask = 0;
-	SERIAL_DRIVER* pSerialSys = SerialSys_s();
+	const SERIAL_DRIVER* pSerialSys = SerialSys_s();
+	WINPR_ASSERT(pWaitMask);
 
-	possibleMask = *pWaitMask & SERCX_SYS_SUPPORTED_EV_MASK;
+	const ULONG possibleMask = *pWaitMask & SERCX_SYS_SUPPORTED_EV_MASK;
 
 	if (possibleMask != *pWaitMask)
 	{