diff --git a/code/modules/unit_tests/_unit_tests.dm b/code/modules/unit_tests/_unit_tests.dm
index 4f0298c36cc..3572b413dfb 100644
--- a/code/modules/unit_tests/_unit_tests.dm
+++ b/code/modules/unit_tests/_unit_tests.dm
@@ -130,6 +130,7 @@
 #include "outfit_sanity.dm"
 #include "paintings.dm"
 #include "pills.dm"
+#include "plane_dupe_detector.dm"
 #include "plantgrowth_tests.dm"
 #include "preference_species.dm"
 #include "preferences.dm"
diff --git a/code/modules/unit_tests/plane_dupe_detector.dm b/code/modules/unit_tests/plane_dupe_detector.dm
new file mode 100644
index 00000000000..c5d8d54e44f
--- /dev/null
+++ b/code/modules/unit_tests/plane_dupe_detector.dm
@@ -0,0 +1,12 @@
+///Checks if we don't have two planes on the same layer
+/datum/unit_test/plane_dupe_detector
+
+/datum/unit_test/plane_dupe_detector/Run()
+	var/list/plane_integer_list = list()
+	for(var/atom/movable/screen/plane_master/plane_path as anything in subtypesof(/atom/movable/screen/plane_master))
+		if(!initial(plane_path.plane))
+			continue
+		if(plane_integer_list.Find("[initial(plane_path.plane)]"))
+			var/atom/movable/screen/plane_master/duplicate_plane_path = plane_integer_list["[initial(plane_path.plane)]"]
+			TEST_FAIL("PLANE CONFLICT DETECTED!! The [initial(plane_path.name)] and [initial(duplicate_plane_path.name)] both use plane [initial(plane_path.plane)].")
+		plane_integer_list["[initial(plane_path.plane)]"] = plane_path