diff --git a/js/src/jsfriendapi.cpp b/js/src/jsfriendapi.cpp
index 4b7ed8efd578..1a58096577e9 100644
--- a/js/src/jsfriendapi.cpp
+++ b/js/src/jsfriendapi.cpp
@@ -214,6 +214,12 @@ js::GetObjectSlotSpan(const JSObject *obj)
     return obj->slotSpan();
 }
 
+JS_FRIEND_API(bool)
+js::IsObjectInContextCompartment(const JSObject *obj, const JSContext *cx)
+{
+    return obj->compartment() == cx->compartment;
+}
+
 JS_FRIEND_API(bool)
 js::IsOriginalScriptFunction(JSFunction *fun)
 {
diff --git a/js/src/jsfriendapi.h b/js/src/jsfriendapi.h
index ad2cb545fac9..5a382c87d98f 100644
--- a/js/src/jsfriendapi.h
+++ b/js/src/jsfriendapi.h
@@ -411,6 +411,9 @@ StringIsArrayIndex(JSLinearString *str, jsuint *indexp);
 JS_FRIEND_API(void)
 SetPreserveWrapperCallback(JSRuntime *rt, PreserveWrapperCallback callback);
 
+JS_FRIEND_API(bool)
+IsObjectInContextCompartment(const JSObject *obj, const JSContext *cx);
+
 /*
  * NB: these flag bits are encoded into the bytecode stream in the immediate
  * operand of JSOP_ITER, so don't change them without advancing jsxdrapi.h's
diff --git a/js/xpconnect/src/XPCConvert.cpp b/js/xpconnect/src/XPCConvert.cpp
index 0ac11b4d2b7f..d3578c223462 100644
--- a/js/xpconnect/src/XPCConvert.cpp
+++ b/js/xpconnect/src/XPCConvert.cpp
@@ -160,7 +160,7 @@ XPCConvert::NativeData2JS(XPCLazyCallContext& lccx, jsval* d, const void* s,
     // Allow wrong compartment or unset ScopeForNewObject when the caller knows
     // the value is primitive (viz., XPCNativeMember::GetConstantValue).
     NS_ABORT_IF_FALSE(type.IsArithmetic() ||
-                      cx->compartment == js::GetObjectCompartment(lccx.GetScopeForNewJSObjects()),
+                      js::IsObjectInContextCompartment(lccx.GetScopeForNewJSObjects(), cx),
                       "bad scope for new JSObjects");
 
     if (pErr)
@@ -933,7 +933,7 @@ XPCConvert::NativeInterface2JSObject(XPCLazyCallContext& lccx,
     // optimal -- we could detect this and roll the functionality into a
     // single wrapper, but the current solution is good enough for now.
     JSContext* cx = lccx.GetJSContext();
-    NS_ABORT_IF_FALSE(js::GetObjectCompartment(lccx.GetScopeForNewJSObjects()) == cx->compartment,
+    NS_ABORT_IF_FALSE(js::IsObjectInContextCompartment(lccx.GetScopeForNewJSObjects(), cx),
                       "bad scope for new JSObjects");
 
     JSObject *jsscope = lccx.GetScopeForNewJSObjects();
@@ -979,7 +979,7 @@ XPCConvert::NativeInterface2JSObject(XPCLazyCallContext& lccx,
             if (!flat) {
                 tryConstructSlimWrapper = true;
             } else if (IS_SLIM_WRAPPER_OBJECT(flat)) {
-                if (js::GetObjectCompartment(flat) == cx->compartment) {
+                if (js::IsObjectInContextCompartment(flat, cx)) {
                     *d = OBJECT_TO_JSVAL(flat);
                     return true;
                 }
@@ -1150,7 +1150,7 @@ XPCConvert::NativeInterface2JSObject(XPCLazyCallContext& lccx,
         } else {
             flat = JS_ObjectToOuterObject(cx, flat);
             NS_ASSERTION(flat, "bad outer object hook!");
-            NS_ASSERTION(js::GetObjectCompartment(flat) == cx->compartment,
+            NS_ASSERTION(js::IsObjectInContextCompartment(flat, cx),
                          "bad compartment");
         }
     }
@@ -1584,7 +1584,7 @@ XPCConvert::NativeArray2JS(XPCLazyCallContext& lccx,
         return false;
 
     JSContext* cx = ccx.GetJSContext();
-    NS_ABORT_IF_FALSE(js::GetObjectCompartment(lccx.GetScopeForNewJSObjects()) == cx->compartment,
+    NS_ABORT_IF_FALSE(js::IsObjectInContextCompartment(lccx.GetScopeForNewJSObjects(), cx),
                       "bad scope for new JSObjects");
 
     // XXX add support for putting chars in a string rather than an array
diff --git a/js/xpconnect/src/XPCInlines.h b/js/xpconnect/src/XPCInlines.h
index 973a1bc42348..8ea20eef87eb 100644
--- a/js/xpconnect/src/XPCInlines.h
+++ b/js/xpconnect/src/XPCInlines.h
@@ -164,7 +164,7 @@ inline void
 XPCCallContext::SetScopeForNewJSObjects(JSObject *scope)
 {
     NS_ABORT_IF_FALSE(mState == HAVE_CONTEXT, "wrong call context state");
-    NS_ABORT_IF_FALSE(js::GetObjectCompartment(scope) == mJSContext->compartment, "wrong compartment");
+    NS_ABORT_IF_FALSE(js::IsObjectInContextCompartment(scope, mJSContext), "wrong compartment");
     mScopeForNewJSObjects = scope;
     mState = HAVE_SCOPE;
 }
diff --git a/js/xpconnect/src/XPCVariant.cpp b/js/xpconnect/src/XPCVariant.cpp
index c25c476a300c..c61ef42b3c59 100644
--- a/js/xpconnect/src/XPCVariant.cpp
+++ b/js/xpconnect/src/XPCVariant.cpp
@@ -466,7 +466,7 @@ XPCVariant::VariantDataToJS(XPCLazyCallContext& lccx,
     JSBool success;
 
     JSContext* cx = lccx.GetJSContext();
-    NS_ABORT_IF_FALSE(js::GetObjectCompartment(lccx.GetScopeForNewJSObjects()) == cx->compartment,
+    NS_ABORT_IF_FALSE(js::IsObjectInContextCompartment(lccx.GetScopeForNewJSObjects(), cx),
                       "bad scope for new JSObjects");
 
     switch (type) {
diff --git a/js/xpconnect/src/XPCWrappedNative.cpp b/js/xpconnect/src/XPCWrappedNative.cpp
index 9d6e8fb1b880..d6f6bdf9c61a 100644
--- a/js/xpconnect/src/XPCWrappedNative.cpp
+++ b/js/xpconnect/src/XPCWrappedNative.cpp
@@ -3683,7 +3683,7 @@ ConstructSlimWrapper(XPCCallContext &ccx,
         return false;
     }
 
-    if (ccx.GetJSContext()->compartment != js::GetObjectCompartment(parent)) {
+    if (!js::IsObjectInContextCompartment(parent, ccx.GetJSContext())) {
         SLIM_LOG_NOT_CREATED(ccx, identityObj, "wrong compartment");
 
         return false;
diff --git a/js/xpconnect/wrappers/WrapperFactory.cpp b/js/xpconnect/wrappers/WrapperFactory.cpp
index 863693941971..5efafbf886d2 100644
--- a/js/xpconnect/wrappers/WrapperFactory.cpp
+++ b/js/xpconnect/wrappers/WrapperFactory.cpp
@@ -437,7 +437,7 @@ WrapperFactory::WaiveXrayAndWrap(JSContext *cx, jsval *vp)
 
     JSObject *obj = js::UnwrapObject(JSVAL_TO_OBJECT(*vp));
     obj = GetCurrentOuter(cx, obj);
-    if (js::GetObjectCompartment(obj) == cx->compartment) {
+    if (js::IsObjectInContextCompartment(obj, cx)) {
         *vp = OBJECT_TO_JSVAL(obj);
         return true;
     }