diff --git a/.gitattributes b/.gitattributes
index 5608bb62882..2bb1f37c187 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1537,6 +1537,7 @@ Envelope_3/test/Envelope_3/data/triangles/test.cin -text
 Envelope_3/test/Envelope_3/data/triangles/test10.cin -text
 Envelope_3/test/Envelope_3/data/triangles/test11.cin -text
 Envelope_3/test/Envelope_3/data/triangles/test12.cin -text
+Envelope_3/test/Envelope_3/data/triangles/test13.cin -text
 Envelope_3/test/Envelope_3/data/triangles/test2.cin -text
 Envelope_3/test/Envelope_3/data/triangles/test3.cin -text
 Envelope_3/test/Envelope_3/data/triangles/test4.cin -text
diff --git a/Envelope_3/test/Envelope_3/data/triangles/test13.cin b/Envelope_3/test/Envelope_3/data/triangles/test13.cin
new file mode 100644
index 00000000000..90580154904
--- /dev/null
+++ b/Envelope_3/test/Envelope_3/data/triangles/test13.cin
@@ -0,0 +1,5 @@
+4
+1 -2 0  -2 -2 3  1 1 3
+0 0 0   3 0 3    0 -3 3
+1 2 0   4 2 3    1 5 3
+1 2 0   4 2 3    1 -1 3