diff --git a/wscompose/convexhull.py b/wscompose/convexhull.py
index 1c112cf..b2d6f59 100644
--- a/wscompose/convexhull.py
+++ b/wscompose/convexhull.py
@@ -36,7 +36,7 @@ def _myDet(p, q, r):
     """Calc. determinant of a special matrix with three 2D points.
 
     The sign, "-" or "+", determines the side, right or left,
-    respectivly, on which the point r lies, when measured against
+    respectively, on which the point r lies, when measured against
     a directed vector from p to q.
     """