diff --git a/ChangeLog b/ChangeLog
index b022ba3a65..a962c8e890 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -16,6 +16,7 @@
 	'sigcode', 'error' parameters with 'detail' parameter.  Fix code
 	accordingly.
 	* mach/mach_error.c (mach_error): Fix old-style function definition.
+	* mach/errstring.c (mach_error_type, mach_error_string): Likewise.
 
 2016-09-20  Paul E. Murphy  <murphyp@linux.vnet.ibm.com>
 
diff --git a/mach/errstring.c b/mach/errstring.c
index 52cf1eb46e..c00b02c2a6 100644
--- a/mach/errstring.c
+++ b/mach/errstring.c
@@ -46,8 +46,7 @@
 extern void __mach_error_map_compat (mach_error_t *);
 
 const char *
-mach_error_type( err )
-	mach_error_t		err;
+mach_error_type(mach_error_t err)
 {
 	int sub, system;
 
@@ -86,8 +85,7 @@ mach_error_string_int(mach_error_t	err,
 }
 
 const char *
-mach_error_string( err )
-	mach_error_t		err;
+mach_error_string(mach_error_t err)
 {
 	boolean_t diag;