diff --git a/switchboard/adapters/lucidly.py b/switchboard/adapters/lucidly.py
index 36c38ad..7a295fa 100644
--- a/switchboard/adapters/lucidly.py
+++ b/switchboard/adapters/lucidly.py
@@ -108,6 +108,9 @@ def __init__(
         self._wallet_total_usd: dict[str, float] = {}
         self._total_parked: float = 0.0
         self._total_yield: float = 0.0
+        # Monotonic suffix so two parks on the same chain at the same clock
+        # value get distinct keys instead of silently overwriting each other.
+        self._position_seq: int = 0
 
     def _target_bps(self, chain: str) -> int:
         return self.config.per_chain_targets.get(chain, self.config.idle_target_bps)
@@ -157,7 +160,8 @@ def rebalance(self, chain: str, liquid_balance_usd: float) -> dict[str, Any]:
                 syUSD_shares=shares,
                 parked_at=self.clock(),
             )
-            self._positions[f"{chain}:{self.clock()}"] = position
+            self._position_seq += 1
+            self._positions[f"{chain}:{self.clock()}:{self._position_seq}"] = position
             self._liquid_buffer[chain] = current_liquid - excess
             self._total_parked += excess
 
diff --git a/tests/test_lucidly.py b/tests/test_lucidly.py
index b0fc224..022325b 100644
--- a/tests/test_lucidly.py
+++ b/tests/test_lucidly.py
@@ -141,3 +141,24 @@ def test_ensure_liquid_unparks_to_threshold_buffer():
 
     assert returned == 500.0
     assert park.status("base")["liquid_buffer_usd"] == 1_500.0
+
+
+def test_two_parks_same_chain_same_clock_are_distinct_positions():
+    # The position key was `chain:clock()`. The adapter takes an injectable
+    # deterministic clock ("Pluggable clock for deterministic tests"), so two
+    # parks on the same chain at the same clock value mapped to the SAME key —
+    # the second ParkedPosition silently overwrote the first, dropping its
+    # per-position yield accrual even though `_total_parked` still counted both.
+    fixed_t = 1_000_000.0
+    park = LucidlyAutoPark(clock=lambda: fixed_t)
+
+    r1 = park.rebalance("base", liquid_balance_usd=10_000.0)
+    r2 = park.rebalance("base", liquid_balance_usd=10_000.0)
+    assert r1["action"] == "parked"
+    assert r2["action"] == "parked"
+
+    report = park.yield_report()
+    # Both park events must be retained as distinct positions, and the position
+    # count must stay consistent with the parked total (which already sums both).
+    assert report["positions"] == 2
+    assert report["total_parked_usd"] == r1["amount_usd"] + r2["amount_usd"]