diff --git a/firmware/inc/semihosting.h b/firmware/inc/semihosting.h
index a657841..a365f8e 100644
--- a/firmware/inc/semihosting.h
+++ b/firmware/inc/semihosting.h
@@ -33,9 +33,11 @@
 #ifndef __SEMIHOSTING__
 
 /* Dummy function handlers */
-#define semihost_putchar(c)
-#define semihost_puts(s)
-#define semihost_printf(...)
+#define semihost_putchar(c)	(void)(c)
+#define semihost_puts(s)	(void)(s)
+#define semihost_printf(...)    __dummy_printf(__VA_ARGS__)
+
+void __dummy_printf(const char *format, ...);
 
 #else
 
@@ -51,6 +53,8 @@ void __putchar(char c);
 void __puts(const char* s);
 void __printf(const char *format, ...);
 
+
+
 #endif /* __SEMIHOSTING__ */
 
 #endif /* SEMIHOSTING_H */
diff --git a/firmware/src/semihosting.c b/firmware/src/semihosting.c
index 1871fcb..ce9cb4d 100644
--- a/firmware/src/semihosting.c
+++ b/firmware/src/semihosting.c
@@ -51,3 +51,6 @@ void __printf(const char *format, ...) {
     vprintf(format, args);
   }
 }
+void __dummy_printf(const char* format, ...) {
+  (void)format;
+}