diff --git a/src/driver/simple_display.cpp b/src/driver/simple_display.cpp
index c7564c014..494dffe30 100644
--- a/src/driver/simple_display.cpp
+++ b/src/driver/simple_display.cpp
@@ -75,7 +75,7 @@ static int proc_put(const char *path, bool state)
 	return ret;
 }
 #else
-static int proc_put(const char, bool) {return 0;}
+static int proc_put(const char *, bool) {return 0;}
 #endif
 
 static char volume = 0;