diff --git a/ui/sdk/src/hamilton_sdk/tracking/polars_col_stats.py b/ui/sdk/src/hamilton_sdk/tracking/polars_col_stats.py
index bb7e43232..cc2f74dd3 100644
--- a/ui/sdk/src/hamilton_sdk/tracking/polars_col_stats.py
+++ b/ui/sdk/src/hamilton_sdk/tracking/polars_col_stats.py
@@ -147,7 +147,7 @@ def datetime_column_stats(
 
 
 def str_len(col: pl.Series) -> pl.Series:
-    return col.str.lengths()
+    return col.str.len_chars()
 
 
 def avg_str_len(str_len: pl.Series) -> float:
diff --git a/ui/sdk/tests/tracking/test_polars_col_stats.py b/ui/sdk/tests/tracking/test_polars_col_stats.py
index 05a54d85a..a20e79385 100644
--- a/ui/sdk/tests/tracking/test_polars_col_stats.py
+++ b/ui/sdk/tests/tracking/test_polars_col_stats.py
@@ -108,3 +108,7 @@ def test_min_string(example_df_string):
 
 def test_max_string(example_df_string):
     assert pcs.max(example_df_string["a"]) == "e"
+
+
+def test_str_len(example_df_string):
+    assert pcs.str_len(example_df_string["a"]).to_list() == [1, 1, 1, 1, 1]