diff --git a/client.go b/client.go
index a6a9ffa2..3eee093b 100644
--- a/client.go
+++ b/client.go
@@ -1047,8 +1047,11 @@ func (c *Client) logStderr(r io.Reader) {
 			}
 		} else {
 			out := flattenKVPairs(entry.KVPairs)
-
-			out = append(out, "timestamp", entry.Timestamp.Format(hclog.TimeFormat))
+			if !entry.Timestamp.IsZero() {
+				// no point in including a zero timestamp
+				// this can happen if the upstream logger has DisableTime set to true
+				out = append(out, "timestamp", entry.Timestamp.Format(hclog.TimeFormat))
+			}
 			switch hclog.LevelFromString(entry.Level) {
 			case hclog.Trace:
 				l.Trace(entry.Message, out...)