diff --git a/plot_transmission_timeline.py b/plot_transmission_timeline.py
index e05dcaf..c7bf2ad 100755
--- a/plot_transmission_timeline.py
+++ b/plot_transmission_timeline.py
@@ -216,7 +216,7 @@ if __name__ == "__main__":
 
     par12.plot(transmission_df["ack_rtt"], "-.", color="red", label="ACK RTT")
     par12.set_ylabel("ACK RTT [s]")
-    par12.set_ylim([0, t])
+    par12.set_ylim([0, 0.5])
 
     par13.plot(transmission_df["goodput"], "-", color="blue", label="goodput")
     par13.set_xlabel("datetime")