diff --git a/radicale/auth/htpasswd.py b/radicale/auth/htpasswd.py
index 1c4b2b55..47f01727 100644
--- a/radicale/auth/htpasswd.py
+++ b/radicale/auth/htpasswd.py
@@ -61,7 +61,7 @@ from typing import Any, Tuple
 
 from passlib.hash import apr_md5_crypt, sha256_crypt, sha512_crypt
 
-from radicale import auth, config, logger
+from radicale import auth, config, logger, utils
 
 
 class Auth(auth.BaseAuth):
@@ -120,12 +120,22 @@ class Auth(auth.BaseAuth):
                         "The htpasswd encryption method 'bcrypt' or 'autodetect' requires "
                         "the bcrypt module (entries found: %d)." % self._htpasswd_bcrypt_use) from e
             else:
-                self._has_bcrypt = True
+                [bcrypt_usable, info] = utils.passlib_libpass_supports_bcrypt()
+                if bcrypt_usable:
+                    self._has_bcrypt = True
+                    logger.debug(info)
+                else:
+                    logger.warning(info)
                 if self._encryption == "autodetect":
                     if self._htpasswd_bcrypt_use == 0:
                         logger.info("auth htpasswd encryption is 'radicale.auth.htpasswd_encryption.%s' and bcrypt module found, but currently not required", self._encryption)
                     else:
                         logger.info("auth htpasswd encryption is 'radicale.auth.htpasswd_encryption.%s' and bcrypt module found (bcrypt entries found: %d)", self._encryption, self._htpasswd_bcrypt_use)
+                        if not bcrypt_usable:
+                            raise RuntimeError("The htpasswd encryption 'autodetect' requires the bcrypt module but not usuable")
+                else:
+                    if not bcrypt_usable:
+                        raise RuntimeError("The htpasswd encryption method 'bcrypt' requires the bcrypt module but not usuable")
             if self._encryption == "bcrypt":
                 self._verify = functools.partial(self._bcrypt, bcrypt)
             else: