diff --git a/mostlyai/engine/_common.py b/mostlyai/engine/_common.py
index 32a627dc..b6434aaa 100644
--- a/mostlyai/engine/_common.py
+++ b/mostlyai/engine/_common.py
@@ -511,7 +511,7 @@ def skip_if_error_wrapper(*args, **kwargs) -> Any:
 
 
 def encode_slen_sidx_sdec(vals: pd.Series, max_seq_len: int, prefix: str = "") -> pd.DataFrame:
-    assert vals.dtype == int or vals.dtype == "int64[pyarrow]"
+    assert is_integer_dtype(vals)
     if max_seq_len < SLEN_SIDX_DIGIT_ENCODING_THRESHOLD or prefix == SDEC_SUB_COLUMN_PREFIX:
         # encode slen and sidx as numeric_discrete
         df = pd.DataFrame({f"{prefix}cat": vals})