diff --git a/windows/syscall_windows.go b/windows/syscall_windows.go
index ce78c5895..6525c62f3 100644
--- a/windows/syscall_windows.go
+++ b/windows/syscall_windows.go
@@ -1864,14 +1864,14 @@ const (
 	CBR_128000 = 128000
 	CBR_256000 = 256000
 
-	DTR_CONTROL_DISABLE   = 0x00
-	DTR_CONTROL_ENABLE    = 0x01
-	DTR_CONTROL_HANDSHAKE = 0x02
-
-	RTS_CONTROL_DISABLE   = 0x00
-	RTS_CONTROL_ENABLE    = 0x01
-	RTS_CONTROL_HANDSHAKE = 0x02
-	RTS_CONTROL_TOGGLE    = 0x03
+	DTR_CONTROL_DISABLE   = 0x00000000
+	DTR_CONTROL_ENABLE    = 0x00000010
+	DTR_CONTROL_HANDSHAKE = 0x00000020
+
+	RTS_CONTROL_DISABLE   = 0x00000000
+	RTS_CONTROL_ENABLE    = 0x00001000
+	RTS_CONTROL_HANDSHAKE = 0x00002000
+	RTS_CONTROL_TOGGLE    = 0x00003000
 
 	NOPARITY    = 0
 	ODDPARITY   = 1
diff --git a/windows/types_windows.go b/windows/types_windows.go
index a3a7ab83e..d8cb71db0 100644
--- a/windows/types_windows.go
+++ b/windows/types_windows.go
@@ -3382,7 +3382,7 @@ type BLOB struct {
 }
 
 type ComStat struct {
-	Flags    [4]uint8
+	Flags    uint32
 	CBInQue  uint32
 	CBOutQue uint32
 }
@@ -3390,7 +3390,7 @@ type ComStat struct {
 type DCB struct {
 	DCBlength  uint32
 	BaudRate   uint32
-	Flags      [4]uint8
+	Flags      uint32
 	wReserved  uint16
 	XonLim     uint16
 	XoffLim    uint16