diff --git a/os/hal/platforms/STM32/OTGv1/usb_lld.h b/os/hal/platforms/STM32/OTGv1/usb_lld.h
index 424d523c5..3b8344e55 100644
--- a/os/hal/platforms/STM32/OTGv1/usb_lld.h
+++ b/os/hal/platforms/STM32/OTGv1/usb_lld.h
@@ -476,14 +476,14 @@ struct USBDriver {
  *
  * @api
  */
-#define usb_lld_connect_bus(usbp) (usbp->otg->GCCFG |= GCCFG_VBUSBSEN)
+#define usb_lld_connect_bus(usbp) ((usbp)->otg->GCCFG |= GCCFG_VBUSBSEN)
 
 /**
  * @brief   Disconnect the USB device.
  *
  * @api
  */
-#define usb_lld_disconnect_bus(usbp) (usbp->otg->GCCFG &= ~GCCFG_VBUSBSEN)
+#define usb_lld_disconnect_bus(usbp) ((usbp)->otg->GCCFG &= ~GCCFG_VBUSBSEN)
 
 /*===========================================================================*/
 /* External declarations.                                                    */
diff --git a/readme.txt b/readme.txt
index ec6d26d47..6b632cf65 100644
--- a/readme.txt
+++ b/readme.txt
@@ -82,6 +82,7 @@
 *****************************************************************************
 
 *** 2.5.2 ***
+- FIX: Fixed missing parenthesis in use of macro arguments (bug 3601638).
 - FIX: Fixed compile errors in Posix-GCC demo (bug 3601621)(backported
   to 2.4.4).
 - FIX: Fixed state checker error in MSP430 port (bug 3601460)(backported