diff --git a/nav.py b/nav.py
index 192ea8e..13b74e5 100644
--- a/nav.py
+++ b/nav.py
@@ -6,7 +6,6 @@ Usage: python3 nav.py DESTINATION
 """
 
 import sys
-import warpdrive
 from collections.abc import Iterator
 
 # Distances between neighboring waypoints, in million km.
@@ -74,7 +73,6 @@ NAMES = {
 CRUISE_SPEED = 0.87  # million km per day
 FUEL_PER_MKM = 0.142  # tonnes of fuel per million km
 LAUNCH_FUEL = 380.0  # tonnes of fuel to escape Earth's gravity
-WARP_FACTOR = warpdrive.calibrate(9.5)
 
 
 def distance(a: str, b: str) -> float: