diff --git a/lib/Plerd/Post.pm b/lib/Plerd/Post.pm
index 00657a4..a142e36 100644
--- a/lib/Plerd/Post.pm
+++ b/lib/Plerd/Post.pm
@@ -398,6 +398,15 @@ sub _build_social_meta_tags {
 
 }
 
+# Normalize CRLF ("Windows") and bare-CR ("classic Mac") newlines to LF, so
+# source files publish cleanly and get rewritten with consistent line endings
+# regardless of the editor that produced them.
+sub _normalize_newlines {
+    my ( $text ) = @_;
+    $text =~ s/\r\n?/\n/g;
+    return $text;
+}
+
 # This next internal method does a bunch of stuff.
 # It's called via Moose-trigger when the object's source_file attribute is set.
 # * Read and store the file's data (body) and metadata
@@ -413,6 +422,7 @@ sub _process_source_file {
     my %attributes;
     my @ordered_attribute_names = qw( title time published_filename guid tags);
     while ( my $line = <$fh> ) {
+        $line = _normalize_newlines( $line );
         chomp $line;
         last unless $line =~ /\S/;
         my ($key, $value) = $line =~ /^\s*(\w+?)\s*:\s*(.*?)\s*$/;
@@ -428,8 +438,8 @@ sub _process_source_file {
     $self->attributes( \%attributes );
 
     my $body;
-    while ( <$fh> ) {
-        $body .= $_;
+    while ( my $line = <$fh> ) {
+        $body .= _normalize_newlines( $line );
     }
 
     close $fh;
diff --git a/t/crlf.t b/t/crlf.t
new file mode 100644
index 0000000..3b249c0
--- /dev/null
+++ b/t/crlf.t
@@ -0,0 +1,65 @@
+use warnings;
+use strict;
+use Test::More;
+use Path::Class::Dir;
+use Path::Class::File;
+use URI;
+
+use FindBin;
+use lib "$FindBin::Bin/../lib";
+
+use_ok( 'Plerd' );
+use Plerd::Init;
+
+# Regression test for GitHub issue #25: source files that use CRLF ("Windows")
+# newlines used to break publication with a misleading "not in W3C format"
+# error. Plerd should accept CRLF source files, publish them cleanly, and
+# normalize the rewritten source file to LF newlines.
+
+my $blog_dir = Path::Class::Dir->new( "$FindBin::Bin/crlf_testblog" );
+$blog_dir->rmtree;
+
+Plerd::Init::initialize( $blog_dir->stringify, 0 );
+
+my $source_file = Path::Class::File->new( $blog_dir, 'source', 'crlf-post.md' );
+{
+    open my $fh, '>:raw', $source_file->stringify
+        or die "Can't write $source_file: $!";
+    print $fh "title: CRLF Post\r\n";
+    print $fh "time: 2018-03-04T12:00:00\r\n";
+    print $fh "tags: foo, bar\r\n";
+    print $fh "\r\n";
+    print $fh "This is the **body** of the post.\r\n";
+    print $fh "\r\n";
+    print $fh "Second paragraph here.\r\n";
+    close $fh;
+}
+
+my $plerd = Plerd->new(
+    path         => $blog_dir->stringify,
+    title        => 'Test Blog',
+    author_name  => 'Nobody',
+    author_email => 'nobody@example.com',
+    base_uri     => URI->new( 'http://blog.example.com/' ),
+);
+
+eval { $plerd->publish_all; };
+is( $@, '', 'A CRLF source file publishes without error.' );
+
+my $published = Path::Class::File->new(
+    $blog_dir, 'docroot', '2018-03-04-crlf-post.html'
+);
+ok( -e $published, 'The CRLF post produced its HTML file.' );
+
+# The source file is rewritten in place during publication; it should no
+# longer contain any carriage returns.
+my $rewritten = do {
+    open my $fh, '<:raw', $source_file->stringify or die $!;
+    local $/;
+    <$fh>;
+};
+unlike( $rewritten, qr/\r/, 'Rewritten source file is free of carriage returns.' );
+
+$blog_dir->rmtree;
+
+done_testing();