diff --git a/tests/bugs/grids.list b/tests/bugs/grids.list
index beba144d4a..ffe5f34afc 100755
--- a/tests/bugs/grids.list
+++ b/tests/bugs/grids.list
@@ -9,14 +9,15 @@
 009 modalg_5
 010 modalg_6
 011 modalg_7
-012 moddata_1
-013 moddata_2
-014 moddata_3
-015 step
-016 caf
-017 mesh
-018 heal
-019 stlvrml
-020 splitshape
-021 splitshape_1
-022 filling
+012 modalg_8
+013 moddata_1
+014 moddata_2
+015 moddata_3
+016 step
+017 caf
+018 mesh
+019 heal
+020 stlvrml
+021 splitshape
+022 splitshape_1
+023 filling
diff --git a/tests/bugs/modalg_8/bug30160 b/tests/bugs/modalg_8/bug30160
new file mode 100644
index 0000000000..0b1813c25b
--- /dev/null
+++ b/tests/bugs/modalg_8/bug30160
@@ -0,0 +1,19 @@
+puts "================================================="
+puts "0030160: DBRep_IsoBuilder builds wrong isolines for planar faces"
+puts "================================================="
+puts ""
+
+restore [locate_data_file OCC1477_bsplinewire_c0.brep] sp
+restore [locate_data_file OCC1477_profile1_circle.brep] pr
+wire pr pr
+
+mksweep sp
+addsweep pr -T -R
+buildsweep res -R -S
+checkshape res
+
+explode res f
+renamevar res_4 result
+isos result 50
+checkprops result -s 208.267
+checkview -display result -2d -path ${imagedir}/${test_image}.png