diff --git a/NEWS b/NEWS
index d64590e5f97..e53b898f996 100644
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,7 @@ PHP                                                                        NEWS
 - Added --ri switch to CLI which allows to check extension information. (Marcus)
 - Added tidyNode::getParent() method (John, Nuno)
 - Fixed zend_llist_remove_tail (Michael Wallner, Dmitry)
+- Fixed bug #40678 (Cross compilation fails). (Tony)
 - Fixed bug #40621 (Crash when constructor called inappropriately). (Tony)
 - Fixed bug #40609 (Segfaults when using more than one SoapVar in a request).
   (Rob, Dmitry)
diff --git a/ext/posix/config.m4 b/ext/posix/config.m4
index f84facde60b..f88e2615ff4 100644
--- a/ext/posix/config.m4
+++ b/ext/posix/config.m4
@@ -28,5 +28,7 @@ int main(int argc, char *argv[])
     AC_DEFINE(HAVE_TTYNAME_R, 1, [Whether you have a working ttyname_r])
   ],[
     AC_MSG_RESULT([no, posix_ttyname() will be thread-unsafe])
+  ], [
+    AC_MSG_RESULT([no, cannot detect working ttyname_r() when cross compiling. posix_ttyname() will be thread-unsafe])
   ])
 fi