diff --git a/libhts/libhts.py b/libhts/libhts.py
index a68c2d622ed87b38d6c9fe23e330275ce59adb49..39ab715317f3d07d0716826216dfac0b75f77b99 100644
--- a/libhts/libhts.py
+++ b/libhts/libhts.py
@@ -462,7 +462,7 @@ def size_factor_correlations(counts_data, summaries, normalizer):
             if str(err) == "array must not contain infs or NaNs":
                 msg = (
                     f"Cannot compute Pearson correlation with size factors "
-                    f"when normalizing using {normaliser}")
+                    f"when normalizing using {normalizer}")
                 warnings.warn(msg)
                 return np.nan
             else: