diff --git a/py-polars/Cargo.lock b/py-polars/Cargo.lock
index d093e9ebfc8c..895d3a7a2e1d 100644
--- a/py-polars/Cargo.lock
+++ b/py-polars/Cargo.lock
@@ -1699,6 +1699,7 @@ dependencies = [
  "hashbrown 0.14.0",
  "num-traits",
  "once_cell",
+ "polars-error",
  "rayon",
  "smartstring",
  "sysinfo",
diff --git a/py-polars/polars/series/series.py b/py-polars/polars/series/series.py
index 3b4fbf31a14d..8353d19b1170 100644
--- a/py-polars/polars/series/series.py
+++ b/py-polars/polars/series/series.py
@@ -3635,9 +3635,18 @@ def to_numpy(
         use_pyarrow: bool = True,
     ) -> np.ndarray[Any, Any]:
         """
-        Convert this Series to numpy. This operation clones data but is completely safe.
+        Convert this Series to numpy.
 
-        If you want a zero-copy view and know what you are doing, use `.view()`.
+        This operation may clone data but is completely safe. Note that:
+
+        - data which is purely numeric AND without null values is not cloned;
+        - floating point ``nan`` values can be zero-copied;
+        - booleans can't be zero-copied.
+
+        To ensure that no data is cloned, set ``zero_copy_only=True``.
+
+        Alternatively, if you want a zero-copy view and know what you are doing,
+        use `.view()`.
 
         Parameters
         ----------