diff --git a/js/src/ds/OrderedHashTable.h b/js/src/ds/OrderedHashTable.h
index c99272129761..a7c8d3452392 100644
--- a/js/src/ds/OrderedHashTable.h
+++ b/js/src/ds/OrderedHashTable.h
@@ -702,16 +702,19 @@ class OrderedHashMap
     typedef typename Impl::Range Range;
 
     explicit OrderedHashMap(AllocPolicy ap = AllocPolicy()) : impl(ap) {}
-    bool init()                                     { return impl.init(); }
+    MOZ_WARN_UNUSED_RESULT bool init()              { return impl.init(); }
     uint32_t count() const                          { return impl.count(); }
     bool has(const Key& key) const                  { return impl.has(key); }
     Range all()                                     { return impl.all(); }
     const Entry* get(const Key& key) const          { return impl.get(key); }
     Entry* get(const Key& key)                      { return impl.get(key); }
-    template <typename V>
-    bool put(const Key& key, V&& value)             { return impl.put(Entry(key, Forward<V>(value))); }
     bool remove(const Key& key, bool* foundp)       { return impl.remove(key, foundp); }
-    bool clear()                                    { return impl.clear(); }
+    MOZ_WARN_UNUSED_RESULT bool clear()             { return impl.clear(); }
+
+    template <typename V>
+    MOZ_WARN_UNUSED_RESULT bool put(const Key& key, V&& value) {
+        return impl.put(Entry(key, Forward<V>(value)));
+    }
 
     void rekeyOneEntry(const Key& current, const Key& newKey) {
         const Entry* e = get(current);
@@ -739,13 +742,13 @@ class OrderedHashSet
     typedef typename Impl::Range Range;
 
     explicit OrderedHashSet(AllocPolicy ap = AllocPolicy()) : impl(ap) {}
-    bool init()                                     { return impl.init(); }
+    MOZ_WARN_UNUSED_RESULT bool init()              { return impl.init(); }
     uint32_t count() const                          { return impl.count(); }
     bool has(const T& value) const                  { return impl.has(value); }
     Range all()                                     { return impl.all(); }
-    bool put(const T& value)                        { return impl.put(value); }
+    MOZ_WARN_UNUSED_RESULT bool put(const T& value) { return impl.put(value); }
     bool remove(const T& value, bool* foundp)       { return impl.remove(value, foundp); }
-    bool clear()                                    { return impl.clear(); }
+    MOZ_WARN_UNUSED_RESULT bool clear()             { return impl.clear(); }
 
     void rekeyOneEntry(const T& current, const T& newKey) {
         return impl.rekeyOneEntry(current, newKey, newKey);
diff --git a/js/src/gc/Marking.cpp b/js/src/gc/Marking.cpp
index 13a6754915c2..8df3c3c6d226 100644
--- a/js/src/gc/Marking.cpp
+++ b/js/src/gc/Marking.cpp
@@ -1764,8 +1764,11 @@ GCMarker::stop()
 
     /* Free non-ballast stack memory. */
     stack.reset();
-    for (GCZonesIter zone(runtime()); !zone.done(); zone.next())
-        zone->gcWeakKeys.clear();
+    AutoEnterOOMUnsafeRegion oomUnsafe;
+    for (GCZonesIter zone(runtime()); !zone.done(); zone.next()) {
+        if (!zone->gcWeakKeys.clear())
+            oomUnsafe.crash("clearing weak keys in GCMarker::stop()");
+    }
 }
 
 void
@@ -1820,8 +1823,11 @@ GCMarker::leaveWeakMarkingMode()
 
     // Table is expensive to maintain when not in weak marking mode, so we'll
     // rebuild it upon entry rather than allow it to contain stale data.
-    for (GCZonesIter zone(runtime()); !zone.done(); zone.next())
-        zone->gcWeakKeys.clear();
+    AutoEnterOOMUnsafeRegion oomUnsafe;
+    for (GCZonesIter zone(runtime()); !zone.done(); zone.next()) {
+        if (!zone->gcWeakKeys.clear())
+            oomUnsafe.crash("clearing weak keys in GCMarker::leaveWeakMarkingMode()");
+    }
 }
 
 void
diff --git a/js/src/jsgc.cpp b/js/src/jsgc.cpp
index 60d93ef26a79..f9586c0c4076 100644
--- a/js/src/jsgc.cpp
+++ b/js/src/jsgc.cpp
@@ -4310,13 +4310,14 @@ js::gc::MarkingValidator::nonIncrementalMark()
         if (!WeakMapBase::saveZoneMarkedWeakMaps(zone, markedWeakMaps))
             return;
 
+        AutoEnterOOMUnsafeRegion oomUnsafe;
         for (gc::WeakKeyTable::Range r = zone->gcWeakKeys.all(); !r.empty(); r.popFront()) {
-            AutoEnterOOMUnsafeRegion oomUnsafe;
             if (!savedWeakKeys.put(Move(r.front().key), Move(r.front().value)))
                 oomUnsafe.crash("saving weak keys table for validator");
         }
 
-        zone->gcWeakKeys.clear();
+        if (!zone->gcWeakKeys.clear())
+            oomUnsafe.crash("clearing weak keys table for validator");
     }
 
     /*
@@ -4387,7 +4388,9 @@ js::gc::MarkingValidator::nonIncrementalMark()
 
     for (GCZonesIter zone(runtime); !zone.done(); zone.next()) {
         WeakMapBase::unmarkZone(zone);
-        zone->gcWeakKeys.clear();
+        AutoEnterOOMUnsafeRegion oomUnsafe;
+        if (!zone->gcWeakKeys.clear())
+            oomUnsafe.crash("clearing weak keys table for validator");
     }
 
     WeakMapBase::restoreMarkedWeakMaps(markedWeakMaps);
@@ -5074,7 +5077,9 @@ GCRuntime::beginSweepingZoneGroup()
         zone->gcWeakRefs.clear();
 
         /* No need to look up any more weakmap keys from this zone group. */
-        zone->gcWeakKeys.clear();
+        AutoEnterOOMUnsafeRegion oomUnsafe;
+        if (!zone->gcWeakKeys.clear())
+            oomUnsafe.crash("clearing weak keys in beginSweepingZoneGroup()");
     }
 
     FreeOp fop(rt);