diff --git a/os/kernel/include/ch.h b/os/kernel/include/ch.h
index d332bd77e..0512fd3e5 100644
--- a/os/kernel/include/ch.h
+++ b/os/kernel/include/ch.h
@@ -69,14 +69,14 @@
  * @brief   Generic 'false' boolean constant.
  */
 #if !defined(FALSE) || defined(__DOXYGEN__)
-#define FALSE                   false
+#define FALSE                   0
 #endif
 
 /**
  * @brief   Generic 'true' boolean constant.
  */
 #if !defined(TRUE) || defined(__DOXYGEN__)
-#define TRUE                    true
+#define TRUE                    !0
 #endif
 
 /**