diff --git a/tests/library/es6.object.assign.ls b/tests/library/es6.object.assign.ls
index 55ea0c75e18b..a7046df869a2 100644
--- a/tests/library/es6.object.assign.ls
+++ b/tests/library/es6.object.assign.ls
@@ -33,6 +33,7 @@ test 'Object.assign' (assert)->
     assert.strictEqual O.b, void, \b
     assert.strictEqual O[c], \c, \c
     assert.strictEqual O[d], void, \d
+    try assert.strictEqual Function('return core.Object.assign({b: 1}, {get a(){delete this.b;},b: 2})')!b, 1
   # test deterministic property order, theoretical can fail with deterministic, but wrong, order
   string = 'abcdefghijklmnopqrst';
   O = {}
diff --git a/tests/library/es7.object.entries.ls b/tests/library/es7.object.entries.ls
index d2deab6ca43a..f95abe0ce2f0 100644
--- a/tests/library/es7.object.entries.ls
+++ b/tests/library/es7.object.entries.ls
@@ -8,4 +8,5 @@ test 'Object.entries' (assert)->
   if \name of entries => assert.strictEqual entries.name, \entries, 'name is "entries"'
   assert.deepEqual entries({q:1, w:2, e:3}), [[\q 1] [\w 2] [\e 3]]
   assert.deepEqual entries(new String \qwe), [[\0 \q] [\1 \w] [\2 \e]]
-  assert.deepEqual entries(assign create({q:1, w:2, e:3}), {a:4, s:5, d:6}), [[\a 4] [\s 5] [\d 6]]
\ No newline at end of file
+  assert.deepEqual entries(assign create({q:1, w:2, e:3}), {a:4, s:5, d:6}), [[\a 4] [\s 5] [\d 6]]
+  try assert.deepEqual Function('return core.Object.entries({a: 1, get b(){delete this.c;return 2},c: 3})')!, [[\a 1], [\b 2]]
\ No newline at end of file
diff --git a/tests/library/es7.object.values.ls b/tests/library/es7.object.values.ls
index 45635e0adf45..b5d39454df25 100644
--- a/tests/library/es7.object.values.ls
+++ b/tests/library/es7.object.values.ls
@@ -8,4 +8,5 @@ test 'Object.values' (assert)->
   if \name of values => assert.strictEqual values.name, \values, 'name is "values"'
   assert.deepEqual values({q:1, w:2, e:3}), [1 2 3]
   assert.deepEqual values(new String \qwe), [\q \w \e]
-  assert.deepEqual values(assign create({q:1, w:2, e:3}), {a:4, s:5, d:6}), [4 5 6]
\ No newline at end of file
+  assert.deepEqual values(assign create({q:1, w:2, e:3}), {a:4, s:5, d:6}), [4 5 6]
+  try assert.deepEqual Function('return core.Object.values({a: 1, get b(){delete this.c;return 2},c: 3})')!, [1 2]
\ No newline at end of file
diff --git a/tests/tests/es6.object.assign.ls b/tests/tests/es6.object.assign.ls
index b2a2ec61c0a4..a5fcd5487361 100644
--- a/tests/tests/es6.object.assign.ls
+++ b/tests/tests/es6.object.assign.ls
@@ -37,6 +37,7 @@ test 'Object.assign' (assert)->
     assert.strictEqual O.b, void, \b
     assert.strictEqual O[c], \c, \c
     assert.strictEqual O[d], void, \d
+    try assert.strictEqual Function('return Object.assign({b: 1}, {get a(){delete this.b;},b: 2})')!b, 1
   # test deterministic property order, theoretical can fail with deterministic, but wrong, order
   string = 'abcdefghijklmnopqrst';
   O = {}
diff --git a/tests/tests/es7.object.entries.ls b/tests/tests/es7.object.entries.ls
index 6368aae59c9e..9c55151ed7c0 100644
--- a/tests/tests/es7.object.entries.ls
+++ b/tests/tests/es7.object.entries.ls
@@ -9,4 +9,5 @@ test 'Object.entries' (assert)->
   assert.strictEqual entries.name, \entries, 'name is "entries"'
   assert.deepEqual entries({q:1, w:2, e:3}), [[\q 1] [\w 2] [\e 3]]
   assert.deepEqual entries(new String \qwe), [[\0 \q] [\1 \w] [\2 \e]]
-  assert.deepEqual entries(assign create({q:1, w:2, e:3}), {a:4, s:5, d:6}), [[\a 4] [\s 5] [\d 6]]
\ No newline at end of file
+  assert.deepEqual entries(assign create({q:1, w:2, e:3}), {a:4, s:5, d:6}), [[\a 4] [\s 5] [\d 6]]
+  try assert.deepEqual Function('return Object.entries({a: 1, get b(){delete this.c;return 2},c: 3})')!, [[\a 1], [\b 2]]
\ No newline at end of file
diff --git a/tests/tests/es7.object.values.ls b/tests/tests/es7.object.values.ls
index f69aa079b098..ecd9f2396f3b 100644
--- a/tests/tests/es7.object.values.ls
+++ b/tests/tests/es7.object.values.ls
@@ -9,4 +9,5 @@ test 'Object.values' (assert)->
   assert.strictEqual values.name, \values, 'name is "values"'
   assert.deepEqual values({q:1, w:2, e:3}), [1 2 3]
   assert.deepEqual values(new String \qwe), [\q \w \e]
-  assert.deepEqual values(assign create({q:1, w:2, e:3}), {a:4, s:5, d:6}), [4 5 6]
\ No newline at end of file
+  assert.deepEqual values(assign create({q:1, w:2, e:3}), {a:4, s:5, d:6}), [4 5 6]
+  try assert.deepEqual Function('return Object.values({a: 1, get b(){delete this.c;return 2},c: 3})')!, [1 2]
\ No newline at end of file