diff --git a/dask_expr/_core.py b/dask_expr/_core.py
index 62f648b8..76148faf 100644
--- a/dask_expr/_core.py
+++ b/dask_expr/_core.py
@@ -151,7 +151,7 @@ def operand(self, key):
 
     def dependencies(self):
         # Dependencies are `Expr` operands only
-        return [operand for operand in operands if isinstance(operand, Expr)]
+        return [operand for operand in self.operands if isinstance(operand, Expr)]
 
     def _task(self, index: int):
         """The task for the i'th partition
diff --git a/dask_expr/tests/test_collection.py b/dask_expr/tests/test_collection.py
index 4d869ca3..4d43e8d7 100644
--- a/dask_expr/tests/test_collection.py
+++ b/dask_expr/tests/test_collection.py
@@ -11,7 +11,7 @@
 import dask.array as da
 import numpy as np
 import pytest
-from dask.dataframe._compat import PANDAS_GE_210
+from dask.dataframe._compat import PANDAS_GE_210, PANDAS_GE_220
 from dask.dataframe.utils import UNKNOWN_CATEGORIES
 from dask.utils import M
 
@@ -1035,6 +1035,7 @@ def test_head_down(df):
     assert not isinstance(optimized.expr, expr.Head)
 
 
+@pytest.mark.skipif(not PANDAS_GE_220, reason="not implemented")
 def test_case_when(pdf, df):
     result = df.x.case_when([(df.x.eq(1), 1), (df.y == 10, 2.5)])
     expected = pdf.x.case_when([(pdf.x.eq(1), 1), (pdf.y == 10, 2.5)])