diff --git a/docs/changes.txt b/docs/changes.txt
index 6604d68f1..f5b333503 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -20,6 +20,7 @@
 - Fixed unexpected non-unique salts in multi-hash cracking in Bitcoin/Litecoin wallet.dat module which lead to false negatives
 - Fixed rare case of misalignment of the status prompt when other user warnings are shown within the hashcat output
 - Fixed password reassembling for cracked hashes on host for slow hashes in optimized mode that are longer than 32 characters
+- Fixed incorrect maximum password length support for -m 400 in optimized mode (reduced from 55 to 39)
 
 ##
 ## Improvements
diff --git a/src/modules/module_00400.c b/src/modules/module_00400.c
index d4ef2f033..def472e8c 100644
--- a/src/modules/module_00400.c
+++ b/src/modules/module_00400.c
@@ -156,6 +156,15 @@ static void phpass_encode (const u8 digest[16], u8 buf[22])
   buf[21] = int_to_itoa64 (l & 0x3f);
 }
 
+u32 module_pw_max (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra)
+{
+  const bool optimized_kernel = (hashconfig->opti_type & OPTI_TYPE_OPTIMIZED_KERNEL);
+
+  const u32 pw_max = (optimized_kernel == true) ? 39 : PW_MAX; // 55 - 16
+
+  return pw_max;
+}
+
 int module_hash_decode (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED void *digest_buf, MAYBE_UNUSED salt_t *salt, MAYBE_UNUSED void *esalt_buf, MAYBE_UNUSED void *hook_salt_buf, MAYBE_UNUSED hashinfo_t *hash_info, const char *line_buf, MAYBE_UNUSED const int line_len)
 {
   u32 *digest = (u32 *) digest_buf;
@@ -282,7 +291,7 @@ void module_init (module_ctx_t *module_ctx)
   module_ctx->module_potfile_disable          = MODULE_DEFAULT;
   module_ctx->module_potfile_keep_all_hashes  = MODULE_DEFAULT;
   module_ctx->module_pwdump_column            = MODULE_DEFAULT;
-  module_ctx->module_pw_max                   = MODULE_DEFAULT;
+  module_ctx->module_pw_max                   = module_pw_max;
   module_ctx->module_pw_min                   = MODULE_DEFAULT;
   module_ctx->module_salt_max                 = MODULE_DEFAULT;
   module_ctx->module_salt_min                 = MODULE_DEFAULT;