diff --git a/docs/changes.txt b/docs/changes.txt
index 14b6c9097..925250f84 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -32,6 +32,7 @@
 - Backend: Changed the maximum number of compute devices from 64 to 128
 - Tests: Improved tests for hash-mode 11300 (Bitcoin/Litecoin wallet.dat)
 - Tests: Improved tests for hash-mode 13600 (WinZip)
+- Tests: Improved tests for hash-mode 16400 (CRAM-MD5 Dovecot)
 - Tests: Improved tests for hash-mode 16800 (WPA-PMKID-PBKDF2)
 
 * changes v5.1.0 -> v6.0.0
diff --git a/tools/test_modules/m16400.pm b/tools/test_modules/m16400.pm
index 277ff48c9..ecab4aeb7 100644
--- a/tools/test_modules/m16400.pm
+++ b/tools/test_modules/m16400.pm
@@ -14,7 +14,9 @@ sub module_constraints { [[0, 64], [-1, -1], [0, 55], [-1, -1], [-1, -1]] }
 
 sub module_generate_hash
 {
-  my $word    = shift;
+  my $word = shift;
+  my $salt = shift;
+  my $end  = shift // "0" x 32;
 
   my $md5 = Digest::Perl::MD5->new;
   my $length = length ($word);
@@ -24,8 +26,8 @@ sub module_generate_hash
   $md5->add ();
 
   my $digest = unpack ("H*", pack ('V4', @{$md5->{_state}}));
- 
-  my $hash = sprintf ("{CRAM-MD5}%s00000000000000000000000000000000", $digest);
+
+  my $hash = sprintf ("{CRAM-MD5}%s%s", $digest, $end);
 
   return $hash;
 }
@@ -43,11 +45,11 @@ sub module_verify_hash
 
   return unless ($signature eq "{CRAM-MD5}");
 
-  my $hash = substr ($digest, 10);
+  my $end = substr ($digest, 42);
 
   my $word_packed = pack_if_HEX_notation ($word);
 
-  my $new_hash = module_generate_hash ($word_packed);
+  my $new_hash = module_generate_hash ($word_packed, "", $end);
 
   return ($new_hash, $word);
 }