diff --git a/nav.py b/nav.py
index 13b74e5..b67440a 100644
--- a/nav.py
+++ b/nav.py
@@ -6,6 +6,7 @@ Usage: python3 nav.py DESTINATION
 """
 
 import sys
+import warpdrive
 from collections.abc import Iterator
 
 # Distances between neighboring waypoints, in million km.
@@ -73,6 +74,7 @@ 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)
 
 
 def distance(a: str, b: str) -> float: