diff --git a/pymc/sampling/forward.py b/pymc/sampling/forward.py
index 5f3c983b58..91f1c6f691 100644
--- a/pymc/sampling/forward.py
+++ b/pymc/sampling/forward.py
@@ -20,8 +20,10 @@
 from collections.abc import Callable, Iterable, Sequence
 from typing import (
     Any,
+    Literal,
     TypeAlias,
     cast,
+    overload,
 )
 
 import numpy as np
@@ -360,6 +362,28 @@ def observed_dependent_deterministics(model: Model, extra_observeds=None):
     ]
 
 
+@overload
+def sample_prior_predictive(
+    draws: int = 500,
+    model: Model | None = None,
+    var_names: Iterable[str] | None = None,
+    random_seed: RandomState = None,
+    return_inferencedata: Literal[True] = True,
+    idata_kwargs: dict | None = None,
+    compile_kwargs: dict | None = None,
+    samples: int | None = None,
+) -> InferenceData: ...
+@overload
+def sample_prior_predictive(
+    draws: int = 500,
+    model: Model | None = None,
+    var_names: Iterable[str] | None = None,
+    random_seed: RandomState = None,
+    return_inferencedata: Literal[False] = False,
+    idata_kwargs: dict | None = None,
+    compile_kwargs: dict | None = None,
+    samples: int | None = None,
+) -> dict[str, np.ndarray]: ...
 def sample_prior_predictive(
     draws: int = 500,
     model: Model | None = None,
diff --git a/tests/sampling/test_forward.py b/tests/sampling/test_forward.py
index 7bbcdc42b1..d3b41bf667 100644
--- a/tests/sampling/test_forward.py
+++ b/tests/sampling/test_forward.py
@@ -857,16 +857,24 @@ def test_logging_sampled_basic_rvs_prior(self, caplog):
             y = pm.Deterministic("y", x + 1)
             z = pm.Normal("z", y, observed=0)
 
+        # all volatile RVs in model
         with m:
             pm.sample_prior_predictive(draws=1)
         assert caplog.record_tuples == [("pymc.sampling.forward", logging.INFO, "Sampling: [x, z]")]
         caplog.clear()
 
+        # `x` has no dependencies so will be sampled by itself
         with m:
             pm.sample_prior_predictive(draws=1, var_names=["x"])
         assert caplog.record_tuples == [("pymc.sampling.forward", logging.INFO, "Sampling: [x]")]
         caplog.clear()
 
+        # `z` depends on `x`
+        with m:
+            pm.sample_prior_predictive(draws=1, var_names=["z"])
+        assert caplog.record_tuples == [("pymc.sampling.forward", logging.INFO, "Sampling: [x, z]")]
+        caplog.clear()
+
     def test_logging_sampled_basic_rvs_posterior(self, caplog):
         with pm.Model() as m:
             x = pm.Normal("x")