diff --git a/wifi_monitor.py b/wifi_monitor.py
index 4700ce4..76d6de0 100755
--- a/wifi_monitor.py
+++ b/wifi_monitor.py
@@ -419,8 +419,12 @@ class CaptureAnalyzer:
     @staticmethod
     def _format_timestamp(pkt):
         """Format packet timestamp as HH:MM:SS.mmm."""
-        if hasattr(pkt, 'time') and pkt.time:
-            dt = datetime.fromtimestamp(pkt.time)
+        if hasattr(pkt, 'time') and pkt.time is not None:
+            try:
+                ts = float(pkt.time)  # pcap can give EDecimal; fromtimestamp needs int/float
+            except (TypeError, ValueError):
+                return "N/A"
+            dt = datetime.fromtimestamp(ts)
             return dt.strftime("%H:%M:%S.%f")[:-3]  # Truncate to milliseconds
         return "N/A"