--- a/js/src/builtin/MapObject.cpp
+++ b/js/src/builtin/MapObject.cpp
@@ -1221,16 +1221,21 @@ MapObject::finalize(FreeOp *fop, JSObjec
 bool
 MapObject::construct(JSContext *cx, unsigned argc, Value *vp)
 {
     Rooted<MapObject*> obj(cx, MapObject::create(cx));
     if (!obj)
         return false;
 
     CallArgs args = CallArgsFromVp(argc, vp);
+
+    // FIXME: bug 1083752
+    if (!WarnIfNotConstructing(cx, args, "Map"))
+        return false;
+
     if (!args.get(0).isNullOrUndefined()) {
         RootedValue adderVal(cx);
         if (!GetProperty(cx, obj, obj, cx->names().set, &adderVal))
             return false;
 
         if (!IsCallable(adderVal))
             return ReportIsNotFunction(cx, adderVal);
 
@@ -1865,16 +1870,21 @@ SetObject::finalize(FreeOp *fop, JSObjec
 bool
 SetObject::construct(JSContext *cx, unsigned argc, Value *vp)
 {
     Rooted<SetObject*> obj(cx, SetObject::create(cx));
     if (!obj)
         return false;
 
     CallArgs args = CallArgsFromVp(argc, vp);
+
+    // FIXME: bug 1083752
+    if (!WarnIfNotConstructing(cx, args, "Set"))
+        return false;
+
     if (!args.get(0).isNullOrUndefined()) {
         RootedValue adderVal(cx);
         if (!GetProperty(cx, obj, obj, cx->names().add, &adderVal))
             return false;
 
         if (!IsCallable(adderVal))
             return ReportIsNotFunction(cx, adderVal);
 

--- a/js/src/jit-test/tests/collections/Map-constructor-1.js
+++ b/js/src/jit-test/tests/collections/Map-constructor-1.js
@@ -1,8 +1,17 @@
 // The Map constructor creates an empty Map by default.
 
+load(libdir + "asserts.js");
+
 var m = new Map();
 assertEq(m.size, 0);
 m = new Map(undefined);
 assertEq(m.size, 0);
 m = new Map(null);
 assertEq(m.size, 0);
+
+// FIXME: bug 1083752
+options("werror");
+assertEq(evaluate("Map()", {catchTermination: true}), "terminated");
+// assertThrowsInstanceOf(() => Map(), TypeError);
+// assertThrowsInstanceOf(() => Map(undefined), TypeError);
+// assertThrowsInstanceOf(() => Map(null), TypeError);

--- a/js/src/jit-test/tests/collections/Set-constructor-1.js
+++ b/js/src/jit-test/tests/collections/Set-constructor-1.js
@@ -1,8 +1,17 @@
 // The Set constructor creates an empty Set by default.
 
+load(libdir + "asserts.js");
+
 var s = new Set();
 assertEq(s.size, 0);
 s = new Set(undefined);
 assertEq(s.size, 0);
 s = new Set(null);
 assertEq(s.size, 0);
+
+// FIXME: bug 1083752
+options("werror");
+assertEq(evaluate("Set()", {catchTermination: true}), "terminated");
+// assertThrowsInstanceOf(() => Set(), TypeError);
+// assertThrowsInstanceOf(() => Set(undefined), TypeError);
+// assertThrowsInstanceOf(() => Set(null), TypeError);

--- a/js/src/jit-test/tests/collections/WeakMap-constructor-1.js
+++ b/js/src/jit-test/tests/collections/WeakMap-constructor-1.js
@@ -1,12 +1,14 @@
 // The WeakMap constructor creates an empty WeakMap by default.
 
 load(libdir + "asserts.js");
 
 new WeakMap();
 new WeakMap(undefined);
 new WeakMap(null);
 
-// FIXME: bug 1062075
+// FIXME: bug 1083752
+options("werror");
+assertEq(evaluate("WeakMap()", {catchTermination: true}), "terminated");
 // assertThrowsInstanceOf(() => WeakMap(), TypeError);
 // assertThrowsInstanceOf(() => WeakMap(undefined), TypeError);
 // assertThrowsInstanceOf(() => WeakMap(null), TypeError);

--- a/js/src/jsweakmap.cpp
+++ b/js/src/jsweakmap.cpp
@@ -15,16 +15,17 @@
 #include "jswrapper.h"
 
 #include "vm/GlobalObject.h"
 #include "vm/WeakMapObject.h"
 
 #include "jsobjinlines.h"
 
 #include "vm/Interpreter-inl.h"
+#include "vm/NativeObject-inl.h"
 
 using namespace js;
 using namespace js::gc;
 
 WeakMapBase::WeakMapBase(JSObject *memOf, JSCompartment *c)
   : memberOf(memOf),
     compartment(c),
     next(WeakMapNotInList),
@@ -521,17 +522,22 @@ JS::SetWeakMapEntry(JSContext *cx, Handl
 static bool
 WeakMap_construct(JSContext *cx, unsigned argc, Value *vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     RootedObject obj(cx, NewBuiltinClassInstance(cx, &WeakMapObject::class_));
     if (!obj)
         return false;
 
-    // ES6 23.3.1.1 steps 5-6, 11.
+    // ES6 draft rev 31 (15 Jan 2015) 23.3.1.1 step 1.
+    // FIXME: bug 1083752
+    if (!WarnIfNotConstructing(cx, args, "WeakMap"))
+        return false;
+
+    // Steps 5-6, 11.
     if (!args.get(0).isNullOrUndefined()) {
         // Steps 7a-b.
         RootedValue adderVal(cx);
         if (!GetProperty(cx, obj, obj, cx->names().set, &adderVal))
             return false;
 
         // Step 7c.
         if (!IsCallable(adderVal))