diff --git a/script/test/TestDiffcalc.py b/script/test/TestDiffcalc.py
index ffd38a8..7e26e9f 100644
--- a/script/test/TestDiffcalc.py
+++ b/script/test/TestDiffcalc.py
@@ -47,7 +47,7 @@ print hkl_to_angles(1, 0, 0)
 #sixc.write([0, 60, 0, 30, 90, 0])
 print "sixch=" , sixch.position
 #wavelenght.write(1.0)
-print "wavelenght = ", wavelenght.read()
+print "wavelength = ", wavelength.read()
 ub.lastub()
 ub.setu ([[1, 0, 0], [0, 1, 0], [0, 0, 1]])
 ub.showref()