diff --git a/Changes b/Changes
index d122f20..f30ae16 100644
--- a/Changes
+++ b/Changes
@@ -9,6 +9,7 @@
         - Introduce --skip-inline-token-annotations parameter
         - Deprecate KORAPXMLTEI_INLINE environment variable
           in favor of --skip-inline-token-annotations
+        - Improve script handling of broken data
 
 1.00 2021-02-18 Release
         - -s option added that uses sentence boundaries
diff --git a/lib/KorAP/XML/TEI.pm b/lib/KorAP/XML/TEI.pm
index 493fce5..aa8cd0f 100644
--- a/lib/KorAP/XML/TEI.pm
+++ b/lib/KorAP/XML/TEI.pm
@@ -115,11 +115,13 @@
 
  CHECK:
 
+  return '' unless $html;
+
   $html =~ s/<!--.*?-->//g; # remove all comments in actual line
 
   # Remove comment spanning over several lines
   # No closing comment found
-  if ( index($html, '-->') == -1) {
+  if (index($html, '-->') == -1) {
 
     # Opening comment found
     $i = index($html, '<!--');
diff --git a/lib/KorAP/XML/TEI/Zipper.pm b/lib/KorAP/XML/TEI/Zipper.pm
index c479239..3f96370 100644
--- a/lib/KorAP/XML/TEI/Zipper.pm
+++ b/lib/KorAP/XML/TEI/Zipper.pm
@@ -3,6 +3,7 @@
 use warnings;
 use Log::Any qw($log);
 use IO::Compress::Zip qw($ZipError :constants);
+use Scalar::Util 'blessed';
 
 # man IO::Compress::Zip
 # At present three compression methods are supported by IO::Compress::Zip, namely
@@ -69,6 +70,10 @@
 
 # Close stream and reset zipper
 sub close {
+  unless (blessed $_[0]->[1]) {
+    $log->fatal("No opened zip file to close");
+    return;
+  };
   $_[0]->[1]->close;
   @{$_[0]} = ($_[0]->[0]);
 };
diff --git a/t/script.t b/t/script.t
index 614ba1d..bd3f28d 100644
--- a/t/script.t
+++ b/t/script.t
@@ -735,4 +735,18 @@
 };
 
 
+subtest 'Broken data testing' => sub {
+  my $file = catfile($f, 'data', 'wikipedia.txt');
+
+  my $t = test_tei2korapxml(
+    tmp => 'script_ginkgo',
+    file => $file,
+    param => '-ti',
+    env => 'KORAPXMLTEI_DEBUG=1'
+  )->stderr_like(qr!No opened zip file to close!)
+  ->stderr_like(qr!Debugging is activated!);
+};
+
+
+
 done_testing;