--- a/aclocal.in
+++ b/aclocal.in
@@ -309,6 +309,12 @@ sub scan_m4_dirs ($@)
foreach my $m4dir (@dirlist)
{
+ if (! -d $m4dir)
+ {
+ msg ('override', "warning: skipping not existing directory `$m4dir'");
+ next;
+ }
+
if (! opendir (DIR, $m4dir))
fatal "couldn't open directory `$m4dir': $!";