diff --git a/geomdl/helpers.py b/geomdl/helpers.py
index <HASH>..<HASH> 100644
--- a/geomdl/helpers.py
+++ b/geomdl/helpers.py
@@ -84,7 +84,7 @@ def find_span_linear(degree, knot_vector, num_ctrlpts, knot, **kwargs):
     :return: knot span
     :rtype: int
     """
-    span = 0  # Knot span index starts from zero
+    span = degree + 1  # Knot span index starts from zero
     while span < num_ctrlpts and knot_vector[span] <= knot:
         span += 1
Fix span finding for out-of-domain evaluation