diff --git a/sources/core/planner.py b/sources/core/planner.py
index 5f99686..4c2abe3 100644
--- a/sources/core/planner.py
+++ b/sources/core/planner.py
@@ -622,12 +622,11 @@ def _verify_required_inputs(self, step: PlanStep) -> tuple[bool, list[str]]:
                 missing_inputs.append(required_input)
         return len(missing_inputs) == 0, missing_inputs
 
-    def _verify_expected_outputs(self, step: PlanStep) -> tuple[bool, list[str]]:
+    def _verify_expected_outputs(self, step: PlanStep | Task) -> tuple[bool, list[str]]:
         """
         Verify that expected outputs files were produced.
         Args:
-            step: The plan step
-            produced_outputs: List of actually produced outputs
+            step: The plan step, or a completed task, declaring expected_outputs
         Returns:
             Tuple[bool, List[str]]: (all_produced, missing_outputs)
         """
@@ -665,9 +664,8 @@ def _can_execute_step(self, step: PlanStep) -> tuple[bool, list[str]]:
             if dep_task is None or dep_task.status != TaskStatus.COMPLETED:
                 missing_deps.append(dep_name)
                 continue
-            expected_outputs = getattr(dep_task, "expected_outputs", None)
-            if expected_outputs:
-                outputs_ok, missing_outputs = self._verify_expected_outputs(expected_outputs)
+            if getattr(dep_task, "expected_outputs", None):
+                outputs_ok, missing_outputs = self._verify_expected_outputs(dep_task)
                 if not outputs_ok:
                     missing_deps.append(
                         f"{dep_name}[missing_outputs:{','.join(missing_outputs)}]"
diff --git a/tests/planner_test.py b/tests/planner_test.py
new file mode 100644
index 0000000..64a352c
--- /dev/null
+++ b/tests/planner_test.py
@@ -0,0 +1,98 @@
+"""Tests for Planner dependency checking.
+
+Focus: ``_can_execute_step`` verifies that a completed dependency actually
+produced the files it declared in ``expected_outputs``.
+"""
+
+import sys
+import tempfile
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).parent.parent))
+
+from sources.core.planner import Planner
+from sources.core.schema import PlanStep, Task, TaskStatus
+
+
+def _planner_with(workspace: str, task_history: list[Task]) -> Planner:
+    """Build a Planner without running its heavy __init__ (EvolutionEngine, LLM)."""
+    planner = object.__new__(Planner)
+    planner.workspace_path = workspace
+    planner.task_history = task_history
+    return planner
+
+
+def _completed_dep(expected_outputs: list[str]) -> Task:
+    return Task(
+        name="step_a",
+        description="produces outputs",
+        status=TaskStatus.COMPLETED,
+        expected_outputs=expected_outputs,
+    )
+
+
+def _dependent_step() -> PlanStep:
+    return PlanStep(
+        name="step_b",
+        goal_context="ctx",
+        task="consume step_a outputs",
+        cost=1,
+        score=0.0,
+        depends_on=["step_a"],
+    )
+
+
+def test_dependency_outputs_present_allows_execution():
+    """A completed dependency whose declared outputs exist unblocks the next step."""
+    with tempfile.TemporaryDirectory() as workspace:
+        (Path(workspace) / "result.csv").write_text("a,b\n1,2\n")
+        planner = _planner_with(workspace, [_completed_dep(["result.csv"])])
+
+        can_execute, missing = planner._can_execute_step(_dependent_step())
+
+    assert can_execute is True
+    assert missing == []
+
+
+def test_dependency_outputs_missing_blocks_execution():
+    """A completed dependency whose declared outputs are absent blocks the next step."""
+    with tempfile.TemporaryDirectory() as workspace:
+        (Path(workspace) / "unrelated.txt").write_text("noise")
+        planner = _planner_with(workspace, [_completed_dep(["result.csv"])])
+
+        can_execute, missing = planner._can_execute_step(_dependent_step())
+
+    assert can_execute is False
+    assert missing == ["step_a[missing_outputs:result.csv]"]
+
+
+def test_dependency_without_declared_outputs_is_not_verified():
+    """A dependency declaring no outputs is treated as satisfied once completed."""
+    with tempfile.TemporaryDirectory() as workspace:
+        planner = _planner_with(workspace, [_completed_dep([])])
+
+        can_execute, missing = planner._can_execute_step(_dependent_step())
+
+    assert can_execute is True
+    assert missing == []
+
+
+def test_incomplete_dependency_blocks_execution():
+    """A dependency that has not completed blocks the next step by name."""
+    with tempfile.TemporaryDirectory() as workspace:
+        pending = _completed_dep(["result.csv"])
+        pending.status = TaskStatus.PENDING
+        planner = _planner_with(workspace, [pending])
+
+        can_execute, missing = planner._can_execute_step(_dependent_step())
+
+    assert can_execute is False
+    assert missing == ["step_a"]
+
+
+if __name__ == "__main__":
+    test_dependency_outputs_present_allows_execution()
+    test_dependency_outputs_missing_blocks_execution()
+    test_dependency_without_declared_outputs_is_not_verified()
+    test_incomplete_dependency_blocks_execution()
+    print("planner dependency tests passed")