grep: enable recurse-submodules to work on <tree> objects

diff --git a/t/t0021/rot13-filter.pl b/t/t0021/rot13-filter.pl
index e3ea58e1ed295e634bece1f3d9180ad20348b608..4d5697ee51c673abbe8a1a90b58bf5b7b9856ce1 100644 (file)
--- a/t/t0021/rot13-filter.pl
+++ b/t/t0021/rot13-filter.pl
@@ -21,6 +21,7 @@
 
 use strict;
 use warnings;
+use IO::File;
 
 my $MAX_PACKET_CONTENT_SIZE = 65516;
 my @capabilities            = @ARGV;