diff --git a/src/factory.cc b/src/factory.cc
index 400132e14b..cccc3e7629 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -576,10 +576,32 @@ Handle<Map> Factory::NewMap(InstanceType type,
 
 
 Handle<JSObject> Factory::NewFunctionPrototype(Handle<JSFunction> function) {
-  CALL_HEAP_FUNCTION(
-      isolate(),
-      isolate()->heap()->AllocateFunctionPrototype(*function),
-      JSObject);
+  // Make sure to use globals from the function's context, since the function
+  // can be from a different context.
+  Handle<Context> native_context(function->context()->native_context());
+  Handle<Map> new_map;
+  if (function->shared()->is_generator()) {
+    // Generator prototypes can share maps since they don't have "constructor"
+    // properties.
+    new_map = handle(native_context->generator_object_prototype_map());
+  } else {
+    // Each function prototype gets a fresh map to avoid unwanted sharing of
+    // maps between prototypes of different constructors.
+    Handle<JSFunction> object_function(native_context->object_function());
+    ASSERT(object_function->has_initial_map());
+    new_map = Map::Copy(handle(object_function->initial_map()));
+  }
+
+  Handle<JSObject> prototype = NewJSObjectFromMap(new_map);
+
+  if (!function->shared()->is_generator()) {
+    JSObject::SetLocalPropertyIgnoreAttributes(prototype,
+                                               constructor_string(),
+                                               function,
+                                               DONT_ENUM);
+  }
+
+  return prototype;
 }
 
 
diff --git a/src/heap.cc b/src/heap.cc
index ecd959da67..30932093be 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -4388,39 +4388,6 @@ void Heap::InitializeFunction(JSFunction* function,
 }
 
 
-MaybeObject* Heap::AllocateFunctionPrototype(JSFunction* function) {
-  // Make sure to use globals from the function's context, since the function
-  // can be from a different context.
-  Context* native_context = function->context()->native_context();
-  Map* new_map;
-  if (function->shared()->is_generator()) {
-    // Generator prototypes can share maps since they don't have "constructor"
-    // properties.
-    new_map = native_context->generator_object_prototype_map();
-  } else {
-    // Each function prototype gets a fresh map to avoid unwanted sharing of
-    // maps between prototypes of different constructors.
-    JSFunction* object_function = native_context->object_function();
-    ASSERT(object_function->has_initial_map());
-    MaybeObject* maybe_map = object_function->initial_map()->Copy();
-    if (!maybe_map->To(&new_map)) return maybe_map;
-  }
-
-  Object* prototype;
-  MaybeObject* maybe_prototype = AllocateJSObjectFromMap(new_map);
-  if (!maybe_prototype->ToObject(&prototype)) return maybe_prototype;
-
-  if (!function->shared()->is_generator()) {
-    MaybeObject* maybe_failure =
-        JSObject::cast(prototype)->SetLocalPropertyIgnoreAttributesTrampoline(
-            constructor_string(), function, DONT_ENUM);
-    if (maybe_failure->IsFailure()) return maybe_failure;
-  }
-
-  return prototype;
-}
-
-
 MaybeObject* Heap::AllocateFunction(Map* function_map,
                                     SharedFunctionInfo* shared,
                                     Object* prototype,
diff --git a/src/heap.h b/src/heap.h
index fc0a2152fd..ea70f076c2 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -672,12 +672,6 @@ class Heap {
   MUST_USE_RESULT MaybeObject* CopyJSObject(JSObject* source,
                                             AllocationSite* site = NULL);
 
-  // Allocates the function prototype.
-  // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation
-  // failed.
-  // Please note this does not perform a garbage collection.
-  MUST_USE_RESULT MaybeObject* AllocateFunctionPrototype(JSFunction* function);
-
   // Allocates a JS ArrayBuffer object.
   // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation
   // failed.