diff --git a/src/include/pc80/mc146818rtc.h b/src/include/pc80/mc146818rtc.h
index fd40308..cf4a951 100644
--- a/src/include/pc80/mc146818rtc.h
+++ b/src/include/pc80/mc146818rtc.h
@@ -220,6 +220,8 @@
 #define CMOS_POST_EXTRA_DEV_PATH  0x01
 
 void cmos_post_log(void);
+#else
+static inline void cmos_post_log(void) {}
 #endif /* CONFIG_CMOS_POST */
 
 #endif /*  PC80_MC146818RTC_H */