diff --git a/encoding.pm b/encoding.pm
index 640a90c..3c8d6a7 100644
--- a/encoding.pm
+++ b/encoding.pm
@@ -371,7 +371,7 @@ Note that C<STDERR> WILL NOT be changed, regardless.
 Also note that non-STD file handles remain unaffected.  Use C<use
 open> or C<binmode> to change the layers of those.
 
-=item C<use encoding I<ENCNAME> Filter=E<gt>1;>
+=item C<use encoding I<ENCNAME>, Filter=E<gt>1;>
 
 This operates as above, but the C<Filter> argument with a non-zero
 value causes the entire script, and not just literals, to be translated from
diff --git a/lib/Encode/Encoding.pm b/lib/Encode/Encoding.pm
index 1df2140..923e05d 100644
--- a/lib/Encode/Encoding.pm
+++ b/lib/Encode/Encoding.pm
@@ -11,7 +11,7 @@ use Carp ();
 use Encode ();
 use Encode::MIME::Name;
 
-sub DEBUG { 0 }
+use constant DEBUG => !!$ENV{PERL_ENCODE_DEBUG};
 
 sub Define {
     my $obj       = shift;
diff --git a/t/guess.t b/t/guess.t
index 81ab91b..896028b 100644
--- a/t/guess.t
+++ b/t/guess.t
@@ -18,11 +18,7 @@ use Encode qw(decode encode find_encoding _utf8_off);
 
 #use Test::More qw(no_plan);
 use Test::More tests => 32;
-use_ok("Encode::Guess");
-{
-    no warnings;
-    $Encode::Guess::DEBUG = shift || 0;
-}
+BEGIN { use_ok("Encode::Guess") }
 
 my $ascii  = join('' => map {chr($_)}(0x21..0x7e));
 my $latin1 = join('' => map {chr($_)}(0xa1..0xfe));