diff --git a/test/staging/sm/extensions/ArrayBuffer-slice-arguments-detaching.js b/test/staging/sm/extensions/ArrayBuffer-slice-arguments-detaching.js
index aa47eae28f..c6b1f3a85b 100644
--- a/test/staging/sm/extensions/ArrayBuffer-slice-arguments-detaching.js
+++ b/test/staging/sm/extensions/ArrayBuffer-slice-arguments-detaching.js
@@ -9,6 +9,7 @@ flags:
 description: |
   ArrayBuffer.prototype.slice shouldn't misbehave horribly if index-argument conversion detaches the ArrayBuffer being sliced
 esid: pending
+features: [host-gc-required]
 ---*/
 
 function testStart()
diff --git a/test/staging/sm/extensions/DataView-construct-arguments-detaching.js b/test/staging/sm/extensions/DataView-construct-arguments-detaching.js
index 7c62eec4a8..4263626604 100644
--- a/test/staging/sm/extensions/DataView-construct-arguments-detaching.js
+++ b/test/staging/sm/extensions/DataView-construct-arguments-detaching.js
@@ -9,6 +9,7 @@ flags:
 description: |
   new DataView(...) shouldn't misbehave horribly if index-argument conversion detaches the ArrayBuffer to be viewed
 esid: pending
+features: [host-gc-required]
 ---*/
 
 function testByteOffset()
diff --git a/test/staging/sm/extensions/DataView-set-arguments-detaching.js b/test/staging/sm/extensions/DataView-set-arguments-detaching.js
index 60d538186d..3b42b9d5d4 100644
--- a/test/staging/sm/extensions/DataView-set-arguments-detaching.js
+++ b/test/staging/sm/extensions/DataView-set-arguments-detaching.js
@@ -9,6 +9,7 @@ flags:
 description: |
   DataView.prototype.set* methods shouldn't misbehave horribly if index-argument conversion detaches the ArrayBuffer being modified
 esid: pending
+features: [host-gc-required]
 ---*/
 
 function testIndex()
diff --git a/test/staging/sm/extensions/dataview.js b/test/staging/sm/extensions/dataview.js
index af1836dbc5..0fba1559c5 100644
--- a/test/staging/sm/extensions/dataview.js
+++ b/test/staging/sm/extensions/dataview.js
@@ -9,6 +9,7 @@ flags:
 description: |
   DataView tests
 esid: pending
+features: [host-gc-required]
 ---*/
 
 function test(sharedMem) {
diff --git a/test/staging/sm/extensions/recursion.js b/test/staging/sm/extensions/recursion.js
index 9aa4dbefca..0828f6221d 100644
--- a/test/staging/sm/extensions/recursion.js
+++ b/test/staging/sm/extensions/recursion.js
@@ -9,6 +9,7 @@ flags:
 description: |
   Handle infinite recursion
 esid: pending
+features: [host-gc-required]
 ---*/
 
 function eval() { eval(); }
diff --git a/test/staging/sm/extensions/regress-650753.js b/test/staging/sm/extensions/regress-650753.js
index 2385ea7372..3695c787cd 100644
--- a/test/staging/sm/extensions/regress-650753.js
+++ b/test/staging/sm/extensions/regress-650753.js
@@ -9,6 +9,7 @@ flags:
 description: |
   pending
 esid: pending
+features: [host-gc-required]
 ---*/
 var x = {}, h = new WeakMap;
 h.set(x, null);
diff --git a/test/staging/sm/extensions/typedarray-set-detach.js b/test/staging/sm/extensions/typedarray-set-detach.js
index 0304e3a204..29aca33688 100644
--- a/test/staging/sm/extensions/typedarray-set-detach.js
+++ b/test/staging/sm/extensions/typedarray-set-detach.js
@@ -9,6 +9,7 @@ flags:
 description: |
   Uint8Array.prototype.set issues when this array changes during setting
 esid: pending
+features: [host-gc-required]
 ---*/
 
 var ab = new ArrayBuffer(200);
diff --git a/test/staging/sm/extensions/weakmap.js b/test/staging/sm/extensions/weakmap.js
index 5ad1b48777..803d71e0d1 100644
--- a/test/staging/sm/extensions/weakmap.js
+++ b/test/staging/sm/extensions/weakmap.js
@@ -9,6 +9,7 @@ flags:
 description: |
   js weak maps
 esid: pending
+features: [host-gc-required]
 ---*/
 
 test();
diff --git a/test/staging/sm/generators/gen-with-call-obj.js b/test/staging/sm/generators/gen-with-call-obj.js
index 3734d03ea4..808f03db18 100644
--- a/test/staging/sm/generators/gen-with-call-obj.js
+++ b/test/staging/sm/generators/gen-with-call-obj.js
@@ -7,6 +7,7 @@ flags:
 description: |
   pending
 esid: pending
+features: [host-gc-required]
 ---*/
 var foo;
 
diff --git a/test/staging/sm/generators/iteration.js b/test/staging/sm/generators/iteration.js
index fb4f3e3458..1ee0041404 100644
--- a/test/staging/sm/generators/iteration.js
+++ b/test/staging/sm/generators/iteration.js
@@ -8,6 +8,7 @@ flags:
 description: |
   pending
 esid: pending
+features: [host-gc-required]
 ---*/
 // This file was written by Andy Wingo <wingo@igalia.com> and originally
 // contributed to V8 as generators-objects.js, available here:
diff --git a/test/staging/sm/object/clear-dictionary-accessor-getset.js b/test/staging/sm/object/clear-dictionary-accessor-getset.js
index 7ec50eb984..19905fb4fc 100644
--- a/test/staging/sm/object/clear-dictionary-accessor-getset.js
+++ b/test/staging/sm/object/clear-dictionary-accessor-getset.js
@@ -9,6 +9,7 @@ flags:
 description: |
   Properly handle GC of a dictionary accessor property whose [[Get]] or [[Set]] has been changed to |undefined|
 esid: pending
+features: [host-gc-required]
 ---*/
 
 function test(field)
diff --git a/test/staging/sm/regress/regress-1507322-deep-weakmap.js b/test/staging/sm/regress/regress-1507322-deep-weakmap.js
index 2f8da0c515..493d4d13de 100644
--- a/test/staging/sm/regress/regress-1507322-deep-weakmap.js
+++ b/test/staging/sm/regress/regress-1507322-deep-weakmap.js
@@ -7,6 +7,7 @@ flags:
 description: |
   pending
 esid: pending
+features: [host-gc-required]
 ---*/
 function TestGC2(m) {
   var head = new Object;
diff --git a/test/staging/sm/regress/regress-592556-c35.js b/test/staging/sm/regress/regress-592556-c35.js
index accb2cfc63..f27c6d6720 100644
--- a/test/staging/sm/regress/regress-592556-c35.js
+++ b/test/staging/sm/regress/regress-592556-c35.js
@@ -9,20 +9,21 @@ flags:
 description: |
   pending
 esid: pending
+features: [host-gc-required]
 ---*/
-
-var obj = {a: 0, b: 1, c: 2};
-delete obj.b;  // switch to dictionary mode
-Object.defineProperty(obj, 'g',
-                      {get: function () { return -1; }, configurable: true});
-for (var i = 3; i < 20; i++)
-    obj['x' + i] = i;  // get property table
-for (var i = 3; i < 20; i++)
-    delete obj['x' + i];  // add to freelist
-delete obj.g;  // must update lastProp->freeslot, to avoid assertion
-
-// extra junk to try to hit the assertion, if freeslot is not updated
-$262.gc();
-obj.d = 3;
-obj.e = 4;
-
+
+var obj = {a: 0, b: 1, c: 2};
+delete obj.b;  // switch to dictionary mode
+Object.defineProperty(obj, 'g',
+                      {get: function () { return -1; }, configurable: true});
+for (var i = 3; i < 20; i++)
+    obj['x' + i] = i;  // get property table
+for (var i = 3; i < 20; i++)
+    delete obj['x' + i];  // add to freelist
+delete obj.g;  // must update lastProp->freeslot, to avoid assertion
+
+// extra junk to try to hit the assertion, if freeslot is not updated
+$262.gc();
+obj.d = 3;
+obj.e = 4;
+
diff --git a/test/staging/sm/regress/regress-596103.js b/test/staging/sm/regress/regress-596103.js
index 558b9d4a0d..36a46af894 100644
--- a/test/staging/sm/regress/regress-596103.js
+++ b/test/staging/sm/regress/regress-596103.js
@@ -9,6 +9,7 @@ flags:
 description: |
   pending
 esid: pending
+features: [host-gc-required]
 ---*/
 for (var u = 0; u < 3; ++u) {
     var y = [];
diff --git a/test/staging/sm/statements/for-in-with-gc-and-unvisited-deletion.js b/test/staging/sm/statements/for-in-with-gc-and-unvisited-deletion.js
index ff8d7fb00d..e78fc11200 100644
--- a/test/staging/sm/statements/for-in-with-gc-and-unvisited-deletion.js
+++ b/test/staging/sm/statements/for-in-with-gc-and-unvisited-deletion.js
@@ -9,6 +9,7 @@ flags:
 description: |
   Don't mishandle deletion of a property from the internal iterator created for a for-in loop, when a gc occurs just after it
 esid: pending
+features: [host-gc-required]
 ---*/
 
 function testOneDeletion()