diff --git a/pycbc/inference/sampler/base_mcmc.py b/pycbc/inference/sampler/base_mcmc.py
index b657468e7a1..14394b449ce 100644
--- a/pycbc/inference/sampler/base_mcmc.py
+++ b/pycbc/inference/sampler/base_mcmc.py
@@ -971,5 +971,5 @@ def ensemble_compute_acl(filename, start_index=None, end_index=None,
                 acl = numpy.inf
             acls[param] = acl
         maxacl = numpy.array(list(acls.values())).max()
-        logging.info("ACT: %s", str(maxacl*fp.thin_interval))
+        logging.info("ACT: %s", str(maxacl*fp.thinned_by))
     return acls
diff --git a/pycbc/inference/sampler/base_multitemper.py b/pycbc/inference/sampler/base_multitemper.py
index 7aaec340e42..fba359babb2 100644
--- a/pycbc/inference/sampler/base_multitemper.py
+++ b/pycbc/inference/sampler/base_multitemper.py
@@ -395,7 +395,7 @@ def ensemble_compute_acl(filename, start_index=None, end_index=None,
                 these_acls[tk] = acl
             acls[param] = these_acls
         maxacl = numpy.array(list(acls.values())).max()
-        logging.info("ACT: %s", str(maxacl*fp.thin_interval))
+        logging.info("ACT: %s", str(maxacl*fp.thinned_by))
     return acls