diff --git a/serialport.c b/serialport.c
index b2e4a79..0a46688 100644
--- a/serialport.c
+++ b/serialport.c
@@ -488,7 +488,7 @@ SP_API enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
 	if (flags & SP_MODE_WRITE)
 		desired_access |= GENERIC_WRITE;
 
-	port->hdl = CreateFile(escaped_port_name, desired_access, 0, 0,
+	port->hdl = CreateFileA(escaped_port_name, desired_access, 0, 0,
 			 OPEN_EXISTING, flags_and_attributes, 0);
 
 	free(escaped_port_name);
diff --git a/windows.c b/windows.c
index 0521716..bc07e23 100644
--- a/windows.c
+++ b/windows.c
@@ -467,9 +467,9 @@ SP_PRIV enum sp_return get_port_details(struct sp_port *port)
 			if (!(escaped_port_name = malloc(strlen(port->name) + 5)))
 				RETURN_ERROR(SP_ERR_MEM, "Escaped port name malloc failed");
 			sprintf(escaped_port_name, "\\\\.\\%s", port->name);
-			handle = CreateFile(escaped_port_name, GENERIC_READ, 0, 0,
-			                    OPEN_EXISTING,
-			                    FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED, 0);
+			handle = CreateFileA(escaped_port_name, GENERIC_READ, 0, 0,
+			                     OPEN_EXISTING,
+			                     FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED, 0);
 			free(escaped_port_name);
 			CloseHandle(handle);