diff --git a/backend/app/services/memory/metrics/collector.py b/backend/app/services/memory/metrics/collector.py
index 154f6e7..7f9ce40 100644
--- a/backend/app/services/memory/metrics/collector.py
+++ b/backend/app/services/memory/metrics/collector.py
@@ -401,8 +401,8 @@ class MemoryMetrics:
             )
 
             # Calculate average latencies
-            retrieval_latencies = self._histograms.get(
-                "memory_retrieval_latency_seconds", []
+            retrieval_latencies = list(
+                self._histograms.get("memory_retrieval_latency_seconds", deque())
             )
             avg_retrieval_latency = (
                 sum(retrieval_latencies) / len(retrieval_latencies)