diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index 9eff4ebce..7c29d88b8 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,7 @@
+2015-06-23  Jon Turney  <jon.turney@dronecode.org.uk>
+
+	* libc/stdio/getchar_u.c: Fix a non-ANSI prototype in SYNOPSIS.
+
 2015-06-23  Jon Turney  <jon.turney@dronecode.org.uk>
 
 	* libc/string/wcscpy.c: Remove stray ',' from prototype in
diff --git a/newlib/libc/stdio/getchar_u.c b/newlib/libc/stdio/getchar_u.c
index 22254cbf5..516b4dbd2 100644
--- a/newlib/libc/stdio/getchar_u.c
+++ b/newlib/libc/stdio/getchar_u.c
@@ -26,7 +26,7 @@ INDEX
 
 SYNOPSIS
 	#include <stdio.h>
-	int getchar_unlocked();
+	int getchar_unlocked(void);
 
 	#include <stdio.h>
 	int _getchar_unlocked_r(struct _reent *<[ptr]>);