1 files changed, 7 insertions, 1 deletions
diff --git a/t/io/open.t b/t/io/open.t
index 5e1b5ec80d..e12b4475d1 100755
--- a/t/io/open.t
+++ b/t/io/open.t
@@ -12,7 +12,7 @@ use Config;
 $Is_VMS = $^O eq 'VMS';
 $Is_MacOS = $^O eq 'MacOS';
 
-plan tests => 107;
+plan tests => 108;
 
 my $Perl = which_perl();
 
@@ -315,3 +315,9 @@ fresh_perl_is(
     'sub f { open(my $fh, "xxx"); $fh = "f"; } f; f;print "ok"',
     'ok', { stderr => 1 },
     '#29102: Crash on assignment to lexical filehandle');
+
+# [perl #31767] Using $1 as a filehandle via open $1, "file" doesn't raise
+# an exception
+
+eval { open $99, "foo" };
+like($@, qr/Modification of a read-only value attempted/, "readonly fh");