diff --git a/dask_cuda/cuda_worker.py b/dask_cuda/cuda_worker.py
index 1d60ffdc..b88c9bc9 100644
--- a/dask_cuda/cuda_worker.py
+++ b/dask_cuda/cuda_worker.py
@@ -168,6 +168,12 @@ def del_pid_file():
         if device_memory_limit is None and memory_limit is None:
             data = lambda _: {}
         elif jit_unspill:
+            if enable_cudf_spill:
+                warnings.warn(
+                    "Enabling cuDF spilling and JIT-Unspill together is not "
+                    "safe, consider disabling JIT-Unspill."
+                )
+
             data = lambda i: (
                 ProxifyHostFile,
                 {
diff --git a/dask_cuda/local_cuda_cluster.py b/dask_cuda/local_cuda_cluster.py
index af99e8ce..202373e9 100644
--- a/dask_cuda/local_cuda_cluster.py
+++ b/dask_cuda/local_cuda_cluster.py
@@ -314,6 +314,12 @@ def __init__(
             if device_memory_limit is None and memory_limit is None:
                 data = {}
             elif jit_unspill:
+                if enable_cudf_spill:
+                    warnings.warn(
+                        "Enabling cuDF spilling and JIT-Unspill together is not "
+                        "safe, consider disabling JIT-Unspill."
+                    )
+
                 data = (
                     ProxifyHostFile,
                     {