diff --git a/src/hflow/resample.py b/src/hflow/resample.py
index 72565438..29242e65 100644
--- a/src/hflow/resample.py
+++ b/src/hflow/resample.py
@@ -28,6 +28,7 @@
 
 import numpy as np
 
+from hflow._field_guards import require_finite_float
 from hflow.format import NANOSECONDS_PER_SECOND
 
 if TYPE_CHECKING:
@@ -238,6 +239,7 @@ def to_grid(
     pinned by ``hflow.format.RESAMPLE_POLICY_VERSION`` (see the module
     docstring).
     """
+    rate_hz = require_finite_float(rate_hz, "rate_hz")
     if rate_hz <= 0.0:
         raise ValueError(f"rate_hz must be positive, got {rate_hz}")
     source_columns = _source_columns(channel, field)
diff --git a/tests/test_resample_derive.py b/tests/test_resample_derive.py
index 9fe877be..2d48a5f1 100644
--- a/tests/test_resample_derive.py
+++ b/tests/test_resample_derive.py
@@ -208,9 +208,19 @@ def test_to_grid_rejects_span_shorter_than_one_step() -> None:
         to_grid(ramp_channel(), 0.01, policy="interpolate")
 
 
-def test_to_grid_rejects_nonpositive_rate() -> None:
-    with pytest.raises(ValueError, match="rate_hz must be positive"):
-        to_grid(ramp_channel(), 0.0, policy="interpolate")
+@pytest.mark.parametrize(
+    ("rate_hz", "message"),
+    [
+        (0.0, "rate_hz must be positive"),
+        (-1.0, "rate_hz must be positive"),
+        (float("nan"), "rate_hz must be finite"),
+        (float("inf"), "rate_hz must be finite"),
+        (float("-inf"), "rate_hz must be finite"),
+    ],
+)
+def test_to_grid_requires_a_finite_positive_rate(rate_hz: float, message: str) -> None:
+    with pytest.raises(ValueError, match=message):
+        to_grid(ramp_channel(), rate_hz, policy="interpolate")
 
 
 def test_derived_series_validates_column_lengths() -> None: