diff --git a/ChangeLog b/ChangeLog
index 88c766f86f..b022ba3a65 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -15,6 +15,7 @@
 	(_hurd_exception2signal): Replace 'exception', 'code', 'subcode',
 	'sigcode', 'error' parameters with 'detail' parameter.  Fix code
 	accordingly.
+	* mach/mach_error.c (mach_error): Fix old-style function definition.
 
 2016-09-20  Paul E. Murphy  <murphyp@linux.vnet.ibm.com>
 
diff --git a/mach/mach_error.c b/mach/mach_error.c
index 8bbb2ec74e..0d3082d021 100644
--- a/mach/mach_error.c
+++ b/mach/mach_error.c
@@ -63,9 +63,7 @@
 extern char * mach_error_string_int(mach_error_t, boolean_t *);
 
 void
-mach_error( str, err )
-	char	*str;
-	mach_error_t		err;
+mach_error(char *str, mach_error_t err)
 {
 	char * err_str;
 	char buf[1024];