diff --git a/bin/pt-archiver b/bin/pt-archiver
index bfe5b2fd..9ff4b638 100755
--- a/bin/pt-archiver
+++ b/bin/pt-archiver
@@ -3962,18 +3962,30 @@ sub main {
    # Open the file and print the header to it. 
    if ( $archive_file ) { 
       my $need_hdr = $o->get('header') && !-f $archive_file; 
-      my $charset  = lc $o->get('charset'); 
-      if ( $charset ) { 
-          $archive_fh = IO::File->new($archive_file, ">>:$charset") 
-             or die "Cannot open $charset $archive_file: $OS_ERROR\n"; 
-      } 
-      else { 
-          $archive_fh = IO::File->new($archive_file, ">>") 
-             or die "Cannot open $archive_file: $OS_ERROR\n"; 
-      } 
+      my $charset  = $o->get('charset') || '';
+      if ($charset eq 'utf8') {
+         $charset = ":$charset";
+      }
+      elsif ($charset) {
+         eval { require Encode }
+            or (PTDEBUG &&
+               _d("Couldn't load Encode: ", $EVAL_ERROR,
+                  "Going to try using the charset ",
+                  "passed in without checking it."));
+         # No need to punish a user if they did their
+         # homework and passed in an official charset,
+         # rather than an alias.
+         $charset = ":encoding("
+                  . (defined &Encode::resolve_alias
+                     ? Encode::resolve_alias($charset) || $charset
+                     : $charset)
+                  . ")";
+      }
+      $archive_fh = IO::File->new($archive_file, ">>$charset") 
+         or die "Cannot open $charset $archive_file: $OS_ERROR\n"; 
       $archive_fh->autoflush(1) unless $o->get('buffer'); 
       if ( $need_hdr ) { 
-         print $archive_fh '', escape(\@sel_cols), "\n" 
+         print { $archive_fh } '', escape(\@sel_cols), "\n" 
             or die "Cannot write to $archive_file: $OS_ERROR\n"; 
       } 
    } 
diff --git a/t/pt-archiver/file.t b/t/pt-archiver/file.t
index 0bde28fe..8a2605da 100644
--- a/t/pt-archiver/file.t
+++ b/t/pt-archiver/file.t
@@ -23,7 +23,7 @@ if ( !$dbh ) {
    plan skip_all => 'Cannot connect to sandbox master';
 }
 else {
-   plan tests => 5;
+   plan tests => 11;
 }
 
 my $output;
@@ -71,6 +71,47 @@ EOF
 , 'File has the right stuff with only some columns');
 `rm -f archive.test.table_1`;
 
+# #############################################################################
+# Bug #903379: --file & --charset could cause warnings and exceptions
+# #############################################################################
+
+sub test_charset {
+   my ($charset) = @_;
+   
+   $sb->load_file('master', 't/pt-archiver/samples/table1.sql');
+   local $@;
+   eval {
+      pt_archiver::main("-c", "b,c", qw(--where 1=1 --header),
+            "--source", "D=test,t=table_1,F=$cnf",
+            '--file', '/tmp/%Y-%m-%d-%D_%H:%i:%s.%t',
+            '--no-check-charset',
+            '--charset', $charset,
+      );
+   };
+
+   ok !$@, "--charset $charset works";
+}
+
+for my $charset (qw(latin1 iso-8859-1 utf8 UTF-8 )) {
+   test_charset($charset);
+}
+
+my $warning;
+local $SIG{__WARN__} = sub { $warning .= shift };
+my $out = output( sub {
+      $sb->load_file('master', 't/pt-archiver/samples/table1.sql');
+      pt_archiver::main("-c", "b,c", qw(--where 1=1 --header),
+            "--source", "D=test,t=table_1,F=$cnf",
+            '--file', '/tmp/%Y-%m-%d-%D_%H:%i:%s.%t',
+            '--no-check-charset',
+            '--charset', "some_charset_that_doesn't_exist",
+      );
+   },
+);
+
+like($out, qr/\QCannot open :encoding(some_chars/, "..but an unknown charset fails");
+like($warning, qr/Cannot find encoding/, "..and throws a useful warning");
+
 # #############################################################################
 # Done.
 # #############################################################################