diff --git a/malariagen_data/anoph/pca.py b/malariagen_data/anoph/pca.py
index d18e2842d..e51d61a69 100644
--- a/malariagen_data/anoph/pca.py
+++ b/malariagen_data/anoph/pca.py
@@ -171,7 +171,6 @@ def pca(
             cohorts=cohorts,
             cohort_size=cohort_size,
             min_cohort_size=min_cohort_size,
-            max_cohort_size=max_cohort_size,
             exclude_samples=exclude_samples,
             fit_exclude_samples=fit_exclude_samples,
             random_seed=random_seed,
@@ -236,7 +235,6 @@ def _pca(
         n_components,
         cohort_size,
         min_cohort_size,
-        max_cohort_size,
         exclude_samples,
         fit_exclude_samples,
         random_seed,
@@ -257,7 +255,7 @@ def _pca(
             site_class=site_class,
             cohort_size=cohort_size,
             min_cohort_size=min_cohort_size,
-            max_cohort_size=max_cohort_size,
+            max_cohort_size=None,
             random_seed=random_seed,
             chunks=chunks,
             inline_array=inline_array,