diff --git a/Makefile.PL b/Makefile.PL
index 9c8f66f..b324098 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -19,6 +19,7 @@ test_requires  'Test::More'      => '0.42';
 test_requires  'Test::Exception' => undef;
 test_requires  'List::MoreUtils' => undef;
 test_requires 'Test::Differences' => undef;
+test_requires 'Test::NoWarnings' => undef;
 test_requires  'FindBin'         => undef;
 
 if ($Module::Install::AUTHOR) {
diff --git a/lib/Text/Markdown.pm b/lib/Text/Markdown.pm
index 1c1f93e..1821315 100644
--- a/lib/Text/Markdown.pm
+++ b/lib/Text/Markdown.pm
@@ -266,6 +266,9 @@ sub urls {
 sub _CleanUpDoc {
     my ($self, $text) = @_;
 
+    # An empty file can end up getting passed as undef.
+    return "\n\n" unless defined $text;
+
     # Standardize line endings:
     $text =~ s{\r\n}{\n}g;  # DOS to Unix
     $text =~ s{\r}{\n}g;    # Mac to Unix
diff --git a/t/05empty_markdown.t b/t/05empty_markdown.t
new file mode 100644
index 0000000..b3aaf72
--- /dev/null
+++ b/t/05empty_markdown.t
@@ -0,0 +1,9 @@
+use strict;
+use warnings;
+use Test::More tests => 3;
+use Text::Markdown;
+use Test::NoWarnings;
+
+my $m = Text::Markdown->new;
+ok $m->markdown(''), 'Parse empty string';
+ok $m->markdown(undef), 'Parse undef';