lib/PublicInbox/TestCommon.pm | 2 ++

diff --git a/lib/PublicInbox/TestCommon.pm b/lib/PublicInbox/TestCommon.pm
index 92a7db36969559f28e358d616c032e84daa24faa..aff34853a88886180849fb35412534ea417f08ca 100644
--- a/lib/PublicInbox/TestCommon.pm
+++ b/lib/PublicInbox/TestCommon.pm
@@ -316,6 +316,7 @@ 		}
 	} else { # localize and run everything in the same process:
 		# note: "local *STDIN = *STDIN;" and so forth did not work in
 		# old versions of perl
+		my $umask = umask;
 		local %ENV = $env ? (%ENV, %$env) : %ENV;
 		local @SIG{keys %SIG} = map { undef } values %SIG;
 		local $SIG{FPE} = 'IGNORE'; # Perl default
@@ -333,6 +334,7 @@ 		eval { PublicInbox::Inbox::cleanup_task() };
 		die "fchdir(restore): $!" if $cwdfh && !chdir($cwdfh);
 		_undo_redirects($orig_io);
 		select STDOUT;
+		umask($umask);
 	}
 
 	# slurp the redirects back into user-supplied strings