diff --git a/src/tests.rs b/src/tests.rs
index 2c7a5f4..182c336 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -109,4 +109,38 @@ mod iteration {
 	    "0", "1", "2", "3", "4", 
 	], "Bad order of elements");
     }
+
+    #[test]
+    fn single_threaded_overlapping_trivial()
+    {
+	let pop = Populator::new(10);
+	for (i, x) in (0..).zip(pop.iter_slice(0..5)) {
+	    _ = x.try_insert(i);
+	}
+	for (i, x) in (0..).zip(pop.iter_slice(3..10)) {
+	    _ = x.try_insert(i);
+	}
+	assert!(pop.try_insert(3, 100).is_err(), "Insertion of completed populator successed when it shouldn't have");
+	assert_eq!(&pop.complete()[..],
+		   [0, 1, 2, 3, 4, 2, 3, 4, 5, 6],
+		   "Overlapping insertions failed");
+    }
+    
+    #[test]
+    fn single_threaded_overlapping_nontrivial()
+    {
+	let pop = Populator::new(10);
+	for (i, x) in (0..).zip(pop.iter_slice(0..5)) {
+	    _ = x.try_insert(i.to_string());
+	}
+	for (i, x) in (0..).zip(pop.iter_slice(3..10)) {
+	    _ = x.try_insert(i.to_string());
+	}
+	assert!(pop.try_insert(3, "hiya".to_string()).is_err(), "Insertion of completed populator successed when it shouldn't have");
+	assert_eq!(&pop.complete()[..],
+		   ["0", "1", "2", "3", "4",
+		    "2", "3", "4", "5", "6"],
+		   "Overlapping insertions failed");
+    }
+    //TODO: multi-threaded overlapping
 }