diff --git a/tests/common.inc b/tests/common.inc
index b78e6a5..9effbd2 100644
--- a/tests/common.inc
+++ b/tests/common.inc
@@ -1,5 +1,6 @@
 # Helper function
 # Get the MD5 sum of the file open at the filehandle
+use Digest::MD5 qw(md5_hex);
 sub md5fh
 {
     my $fh_orig = shift;
diff --git a/tests/normal.pl b/tests/normal.pl
index 6d0658b..468eeb0 100644
--- a/tests/normal.pl
+++ b/tests/normal.pl
@@ -7,7 +7,6 @@ use File::Path;
 use File::Copy;
 use File::Temp;
 use IO::Handle;
-use Digest::MD5 qw(md5_hex);
 
 require("tests/common.inc");
 
diff --git a/tests/reverse.pl b/tests/reverse.pl
index de010cf..cc3f3af 100755
--- a/tests/reverse.pl
+++ b/tests/reverse.pl
@@ -109,12 +109,19 @@ sub grow {
     my $max = 9000;
     for($i=5; $i < $max; $i += 5)
     {
-        print($pfh "wwwww") or die("write failed");
+        print($pfh "abcde") or die("write failed");
         # autoflush should make sure the write goes to the kernel
         # immediately. Just to be sure, check it here.
         sizeVerify($vfh, $i) or die("unexpected plain file size");
         sizeVerify($cfh, $i+8) or $ok = 0;
         sizeVerify($dfh, $i) or $ok = 0;
+        
+        if(md5fh($vfh) ne md5fh($dfh))
+        {
+            $ok = 0;
+            print("# content is different, unified diff:\n");
+            system("diff -u $plain/grow $decrypted/grow");
+        }
 
         last unless $ok;
     }