diff --git a/crates/polars-plan/src/dsl/python_udf.rs b/crates/polars-plan/src/dsl/python_udf.rs
index 521e3a7809e8..e99ec56f14d5 100644
--- a/crates/polars-plan/src/dsl/python_udf.rs
+++ b/crates/polars-plan/src/dsl/python_udf.rs
@@ -57,7 +57,7 @@ impl PythonUdfExpression {
         // Handle pickle metadata
         let use_cloudpickle = buf[0];
         if use_cloudpickle != 0 {
-            let ser_py_version = &buf[..2];
+            let ser_py_version = &buf[1..3];
             let cur_py_version = *PYTHON3_VERSION;
             polars_ensure!(
                 ser_py_version == cur_py_version,