diff --git a/configure b/configure
index 2d2132792b2..47c1d5ea992 100755
--- a/configure
+++ b/configure
@@ -3249,9 +3249,9 @@ if test -z "$MACHDEP"
 then
     # avoid using uname for cross builds
     if test "$cross_compiling" = yes; then
-       # ac_sys_system and ac_sys_release are only used for setting
-       # `define_xopen_source' in the case statement below. For the
-       # current supported cross builds, this macro is not adjusted.
+       # ac_sys_system and ac_sys_release are used for setting
+       # a lot of different things including 'define_xopen_source'
+       # in the case statement below.
 	case "$host" in
 	*-*-linux*)
 		ac_sys_system=Linux
diff --git a/configure.ac b/configure.ac
index 1f520c2afcf..b998b2481c2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -352,9 +352,9 @@ if test -z "$MACHDEP"
 then
     # avoid using uname for cross builds
     if test "$cross_compiling" = yes; then
-       # ac_sys_system and ac_sys_release are only used for setting
-       # `define_xopen_source' in the case statement below. For the
-       # current supported cross builds, this macro is not adjusted.
+       # ac_sys_system and ac_sys_release are used for setting
+       # a lot of different things including 'define_xopen_source'
+       # in the case statement below.
 	case "$host" in
 	*-*-linux*)
 		ac_sys_system=Linux