diff --git a/test/built-ins/FinalizationGroup/prototype/cleanupSome/cleanup-prevented-with-reference.js b/test/built-ins/FinalizationGroup/prototype/cleanupSome/cleanup-prevented-with-reference.js
new file mode 100644
index 0000000000..bfff3426de
--- /dev/null
+++ b/test/built-ins/FinalizationGroup/prototype/cleanupSome/cleanup-prevented-with-reference.js
@@ -0,0 +1,48 @@
+// Copyright (C) 2019 Leo Balter. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-finalization-group.prototype.cleanupSome
+description: Cleanup might be prevented with a reference usage;
+info: |
+  FinalizationGroup.prototype.cleanupSome ( [ callback ] )
+
+  1. Let finalizationGroup be the this value.
+  2. If Type(finalizationGroup) is not Object, throw a TypeError exception.
+  3. If finalizationGroup does not have a [[Cells]] internal slot, throw a TypeError exception.
+  4. If callback is not undefined and IsCallable(callback) is false, throw a TypeError exception.
+  5. Perform ? CleanupFinalizationGroup(finalizationGroup, callback).
+  6. Return undefined.
+features: [FinalizationGroup, arrow-function, async-functions, async-iteration, class, host-gc-required]
+---*/
+
+var holdingsList;
+function cb(iterator) {
+  holdingsList = [...iterator];
+};
+var fg = new FinalizationGroup(function() {});
+
+function emptyCells() {
+  var x;
+  (function() {
+    var a = {};
+    b = {};
+    x = {};
+    var y = {};
+    fg.register(x, 'x');
+    fg.register(a, 'a');
+    fg.register(y, y);
+    fg.register(b, 'b');
+    var b;
+  })();
+  $262.gc();
+  x; // This is an intentional reference to x, please leave it here, after the GC
+}
+
+emptyCells();
+fg.cleanupSome(cb);
+
+// The order is per implementation so we can't use compareArray without sorting
+assert.sameValue(holdingsList.length, 2);
+assert(holdingsList.includes('a'));
+assert(holdingsList.includes('b'));
diff --git a/test/built-ins/FinalizationGroup/prototype/register/holdings-any-value-type.js b/test/built-ins/FinalizationGroup/prototype/register/holdings-any-value-type.js
index a399a4bdb3..1048a07b81 100644
--- a/test/built-ins/FinalizationGroup/prototype/register/holdings-any-value-type.js
+++ b/test/built-ins/FinalizationGroup/prototype/register/holdings-any-value-type.js
@@ -30,8 +30,6 @@ assert.sameValue(fg.register(target, false), undefined, 'false');
 assert.sameValue(fg.register(target, true), undefined, 'true');
 assert.sameValue(fg.register(target, Symbol()), undefined, 'symbol');
 assert.sameValue(fg.register(target, {}), undefined, 'object');
-assert.sameValue(fg.register(target, target), undefined, 'same as target');
 assert.sameValue(fg.register(target, fg), undefined, 'same as fg instance');
-assert.sameValue(fg.register(target, target, target), undefined, 'target, and same as unregisterToken');
 assert.sameValue(fg.register(target, 1), undefined, 'number');
 assert.sameValue(fg.register(target, 'holdings'), undefined, 'string');
diff --git a/test/built-ins/FinalizationGroup/prototype/register/holdings-same-as-target.js b/test/built-ins/FinalizationGroup/prototype/register/holdings-same-as-target.js
new file mode 100644
index 0000000000..d38d8884b9
--- /dev/null
+++ b/test/built-ins/FinalizationGroup/prototype/register/holdings-same-as-target.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2019 Leo Balter. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-finalization-group.prototype.register
+description: holdings may be the same as target
+info: |
+  FinalizationGroup.prototype.register ( target , holdings [, unregisterToken ] )
+
+  1. Let finalizationGroup be the this value.
+  2. If Type(finalizationGroup) is not Object, throw a TypeError exception.
+  3. If Type(target) is not Object, throw a TypeError exception.
+  4. If finalizationGroup does not have a [[Cells]] internal slot, throw a TypeError exception.
+  5. If Type(unregisterToken) is not Object,
+    a. If unregisterToken is not undefined, throw a TypeError exception.
+    b. Set unregisterToken to empty.
+  6. Let cell be the Record { [[Target]] : target, [[Holdings]]: holdings, [[UnregisterToken]]: unregisterToken }.
+  7. Append cell to finalizationGroup.[[Cells]].
+  8. Return undefined.
+features: [FinalizationGroup]
+---*/
+
+var fg = new FinalizationGroup(function() {});
+
+var target = {};
+assert.sameValue(fg.register(target, target), undefined);
diff --git a/test/built-ins/FinalizationGroup/prototype/register/unregisterToken-same-as-holdings-and-target.js b/test/built-ins/FinalizationGroup/prototype/register/unregisterToken-same-as-holdings-and-target.js
new file mode 100644
index 0000000000..f1dc302f4d
--- /dev/null
+++ b/test/built-ins/FinalizationGroup/prototype/register/unregisterToken-same-as-holdings-and-target.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2019 Leo Balter. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-finalization-group.prototype.register
+description: unregisterToken may be the same as holdings and target
+info: |
+  FinalizationGroup.prototype.register ( target , holdings [, unregisterToken ] )
+
+  1. Let finalizationGroup be the this value.
+  2. If Type(finalizationGroup) is not Object, throw a TypeError exception.
+  3. If Type(target) is not Object, throw a TypeError exception.
+  4. If finalizationGroup does not have a [[Cells]] internal slot, throw a TypeError exception.
+  5. If Type(unregisterToken) is not Object,
+    a. If unregisterToken is not undefined, throw a TypeError exception.
+    b. Set unregisterToken to empty.
+  6. Let cell be the Record { [[Target]] : target, [[Holdings]]: holdings, [[UnregisterToken]]: unregisterToken }.
+  7. Append cell to finalizationGroup.[[Cells]].
+  8. Return undefined.
+features: [FinalizationGroup]
+---*/
+
+var fg = new FinalizationGroup(function() {});
+
+var target = {};
+assert.sameValue(fg.register(target, target, target), undefined);
diff --git a/test/built-ins/FinalizationGroup/prototype/register/unregisterToken-same-as-holdings.js b/test/built-ins/FinalizationGroup/prototype/register/unregisterToken-same-as-holdings.js
new file mode 100644
index 0000000000..7c498bc04f
--- /dev/null
+++ b/test/built-ins/FinalizationGroup/prototype/register/unregisterToken-same-as-holdings.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2019 Leo Balter. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-finalization-group.prototype.register
+description: unregisterToken may be the same as holdings
+info: |
+  FinalizationGroup.prototype.register ( target , holdings [, unregisterToken ] )
+
+  1. Let finalizationGroup be the this value.
+  2. If Type(finalizationGroup) is not Object, throw a TypeError exception.
+  3. If Type(target) is not Object, throw a TypeError exception.
+  4. If finalizationGroup does not have a [[Cells]] internal slot, throw a TypeError exception.
+  5. If Type(unregisterToken) is not Object,
+    a. If unregisterToken is not undefined, throw a TypeError exception.
+    b. Set unregisterToken to empty.
+  6. Let cell be the Record { [[Target]] : target, [[Holdings]]: holdings, [[UnregisterToken]]: unregisterToken }.
+  7. Append cell to finalizationGroup.[[Cells]].
+  8. Return undefined.
+features: [FinalizationGroup]
+---*/
+
+var fg = new FinalizationGroup(function() {});
+
+var target = {};
+var holdings = {};
+assert.sameValue(fg.register(target, holdings, holdings), undefined);
diff --git a/test/built-ins/FinalizationGroup/prototype/register/unregisterToken-same-as-target.js b/test/built-ins/FinalizationGroup/prototype/register/unregisterToken-same-as-target.js
new file mode 100644
index 0000000000..20fe2e0563
--- /dev/null
+++ b/test/built-ins/FinalizationGroup/prototype/register/unregisterToken-same-as-target.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2019 Leo Balter. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-finalization-group.prototype.register
+description: unregisterToken may be the same as target
+info: |
+  FinalizationGroup.prototype.register ( target , holdings [, unregisterToken ] )
+
+  1. Let finalizationGroup be the this value.
+  2. If Type(finalizationGroup) is not Object, throw a TypeError exception.
+  3. If Type(target) is not Object, throw a TypeError exception.
+  4. If finalizationGroup does not have a [[Cells]] internal slot, throw a TypeError exception.
+  5. If Type(unregisterToken) is not Object,
+    a. If unregisterToken is not undefined, throw a TypeError exception.
+    b. Set unregisterToken to empty.
+  6. Let cell be the Record { [[Target]] : target, [[Holdings]]: holdings, [[UnregisterToken]]: unregisterToken }.
+  7. Append cell to finalizationGroup.[[Cells]].
+  8. Return undefined.
+features: [FinalizationGroup]
+---*/
+
+var fg = new FinalizationGroup(function() {});
+
+var target = {};
+assert.sameValue(fg.register(target, '1', target), undefined);