diff --git a/testscour.py b/testscour.py
index 93e6d6f..8ebaf9d 100755
--- a/testscour.py
+++ b/testscour.py
@@ -1240,7 +1240,7 @@ class CollapseStraightPathSegments(unittest.TestCase):
                               'm0 0h10 20',
                               'm0 0h10 20',
                               'm0 0h10 20',
-                              'm0 0 20 40',
+                              'm0 0 20 40v1l10 20',
                               'm0 0 10 10-20-20 10 10-20-20',
                               'm0 0 1 2m1 2 2 4m1 2 2 4',
                               'm6.3228 7.1547 81.198 45.258']
diff --git a/unittests/collapse-straight-path-segments.svg b/unittests/collapse-straight-path-segments.svg
index 10541d2..fa8e030 100644
--- a/unittests/collapse-straight-path-segments.svg
+++ b/unittests/collapse-straight-path-segments.svg
@@ -21,8 +21,9 @@
  <path d="m0 0h10 20" style="marker:url(#dot)"/>
  <path d="m0 0h10 20" style="marker-mid:url(#dot)"/>
 
- <!-- all lineto commands should be collapsed into a single (implicit if possible) lineto command -->
- <path d="m 0 0 l 10 20 0.25 0.5 l 0.75 1.5 l 5 10 0.2 0.4 l 3 6 0.8 1.6"/>
+ <!-- all consecutive lineto commands pointing into the sam direction
+      should be collapsed into a single (implicit if possible) lineto command -->
+ <path d="m 0 0 l 10 20 0.25 0.5 l 0.75 1.5 l 5 10 0.2 0.4 l 3 6 0.8 1.6 l 0 1 l 1 2 9 18"/>
  <!-- must not be collapsed (same slope, but different direction) -->
  <path d="m 0 0 10 10 -20 -20 l 10 10 -20 -20"/>
  <!-- first parameter pair of a moveto subpath must not be collapsed as it's not drawn on canvas -->