diff --git a/os/hal/ports/STM32F4xx/hal_lld.h b/os/hal/ports/STM32F4xx/hal_lld.h
index 076c621b7..349adc704 100644
--- a/os/hal/ports/STM32F4xx/hal_lld.h
+++ b/os/hal/ports/STM32F4xx/hal_lld.h
@@ -54,7 +54,7 @@
  */
 #if defined(STM32F40XX) || defined(__DOXYGEN__)
 #define PLATFORM_NAME           "STM32F40x/STM32F41x High Performance"
-#if defined(STM32F42XX)
+#elif defined(STM32F42XX)
 #define PLATFORM_NAME           "STM32F42x/STM32F43x High Performance"
 #else /* !defined(STM32F40XX) */
 #define PLATFORM_NAME           "STM32F2xx High Performance"
@@ -567,6 +567,13 @@
 /* Derived constants and error checks.                                       */
 /*===========================================================================*/
 
+/*
+ * MCU variant check.
+ */
+#if defined(STM32F42XX)
+#error "unsupported STM32F4XX variant"
+#endif
+
 #if defined(STM32F40XX) || defined(__DOXYGEN__)
 /*
  * Configuration-related checks.