diff --git a/winpr/libwinpr/io/device.c b/winpr/libwinpr/io/device.c
index 0e13092d7..2a1b7f8fd 100644
--- a/winpr/libwinpr/io/device.c
+++ b/winpr/libwinpr/io/device.c
@@ -138,7 +138,7 @@ NTSTATUS _IoCreateDeviceEx(PDRIVER_OBJECT_EX DriverObject, ULONG DeviceExtension
 
 	if (!PathFileExistsA(DeviceBasePath))
 	{
-		if (!mkdir(DeviceBasePath, S_IRUSR | S_IWUSR | S_IXUSR))
+		if (mkdir(DeviceBasePath, S_IRUSR | S_IWUSR | S_IXUSR) != 0)
 		{
 			free(DeviceBasePath);
 			return STATUS_ACCESS_DENIED;