lib/PublicInbox/SpawnPP.pm | 6 ++++--

diff --git a/lib/PublicInbox/SpawnPP.pm b/lib/PublicInbox/SpawnPP.pm
index 25c8c87fd86747ffb9fb7466cd4223d83419813a..29b1337103f59c164a6bd1c2fe79ea2d125cc743 100644
--- a/lib/PublicInbox/SpawnPP.pm
+++ b/lib/PublicInbox/SpawnPP.pm
@@ -38,11 +38,13 @@ 			dup2($err, 2) or die "dup2 failed for stderr: $!";
 		}
 
 		if ($ENV{MOD_PERL}) {
-			exec qw(env -i), @$env, @$cmd;
+			exec which('env'), '-i', @$env, @$cmd;
 			die "exec env -i ... $cmd->[0] failed: $!\n";
 		} else {
 			local %ENV = map { split(/=/, $_, 2) } @$env;
-			exec @$cmd;
+			my @cmd = @$cmd;
+			$cmd[0] = $f;
+			exec @cmd;
 			die "exec $cmd->[0] failed: $!\n";
 		}
 	}