diff --git a/tests/bugs/modalg_6/bug21875 b/tests/bugs/modalg_6/bug21875
new file mode 100644
index 0000000000..a5ff09a536
--- /dev/null
+++ b/tests/bugs/modalg_6/bug21875
@@ -0,0 +1,18 @@
+puts "=========="
+puts "OCC21875"
+puts "=========="
+puts ""
+##################################################
+# Section of face by plane produces invalid result
+##################################################
+
+restore [locate_data_file bug21875_face.brep] a
+plane p 0 0 1.844 0 0 1
+mkface f p -10 10 -10 10
+
+bsection result a f
+
+checknbshapes result -edge 5
+checkprops result -l 2.14222
+
+set 2dviewer 1