diff --git a/build/premake/extern_libs4.lua b/build/premake/extern_libs4.lua
index ad5111fda5..899d289f88 100644
--- a/build/premake/extern_libs4.lua
+++ b/build/premake/extern_libs4.lua
@@ -611,7 +611,6 @@ extern_lib_defs = {
 				if not _OPTIONS["android"] then
 					pkgconfig_cflags("mozjs-31")
 				end
-				defines { "WITH_SYSTEM_MOZJS31" }
 			else
 				if os.is("windows") then
 					include_dir = "include-win32"
diff --git a/source/scriptinterface/ScriptInterface.cpp b/source/scriptinterface/ScriptInterface.cpp
index 62851b4f6b..5dad7f8795 100644
--- a/source/scriptinterface/ScriptInterface.cpp
+++ b/source/scriptinterface/ScriptInterface.cpp
@@ -1102,16 +1102,6 @@ void* ScriptInterface::GetPrivate(JS::HandleObject obj)
 	return JS_GetPrivate(obj);
 }
 
-void ScriptInterface::DumpHeap()
-{
-#if MOZJS_DEBUG_ABI
-	JS_DumpHeap(GetJSRuntime(), stderr, NULL, JSTRACE_OBJECT, NULL, (size_t)-1, NULL);
-#endif
-	fprintf(stderr, "# Bytes allocated: %u\n", JS_GetGCParameter(GetJSRuntime(), JSGC_BYTES));
-	JS_GC(GetJSRuntime());
-	fprintf(stderr, "# Bytes allocated after GC: %u\n", JS_GetGCParameter(GetJSRuntime(), JSGC_BYTES));
-}
-
 void ScriptInterface::MaybeGC()
 {
 	JS_MaybeGC(m->m_cx);
diff --git a/source/scriptinterface/ScriptInterface.h b/source/scriptinterface/ScriptInterface.h
index d2c216816f..f925307237 100644
--- a/source/scriptinterface/ScriptInterface.h
+++ b/source/scriptinterface/ScriptInterface.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2015 Wildfire Games.
+/* Copyright (C) 2016 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -313,11 +313,6 @@ public:
 	 */
 	template<typename T> static void ToJSVal(JSContext* cx, JS::MutableHandleValue ret, T const& val);
 
-	/**
-	 * Dump some memory heap debugging information to stderr.
-	 */
-	void DumpHeap();
-
 	/**
 	 * MaybeGC tries to determine whether garbage collection in cx's runtime would free up enough memory to be worth the amount of time it would take.
 	 * This calls JS_MaybeGC directly, which does not do incremental GC. Usually you should prefer MaybeIncrementalRuntimeGC.
diff --git a/source/scriptinterface/ScriptTypes.h b/source/scriptinterface/ScriptTypes.h
index 95c589fb3f..82e6a42ddc 100644
--- a/source/scriptinterface/ScriptTypes.h
+++ b/source/scriptinterface/ScriptTypes.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2014 Wildfire Games.
+/* Copyright (C) 2016 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -28,14 +28,6 @@
 # endif
 #endif
 
-// Guess whether the library was compiled with the release-mode or debug-mode ABI
-// (for JS_DumpHeap etc)
-#if defined(DEBUG) && !defined(WITH_SYSTEM_MOZJS31)
-# define MOZJS_DEBUG_ABI 1
-#else
-# define MOZJS_DEBUG_ABI 0
-#endif
-
 // Ignore some harmless warnings
 #if GCC_VERSION
 # pragma GCC diagnostic push
diff --git a/source/simulation2/Simulation2.cpp b/source/simulation2/Simulation2.cpp
index f868dc9ae6..9ce2138135 100644
--- a/source/simulation2/Simulation2.cpp
+++ b/source/simulation2/Simulation2.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2015 Wildfire Games.
+/* Copyright (C) 2016 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -444,9 +444,6 @@ void CSimulation2Impl::Update(int turnLength, const std::vector<SimulationComman
 		}
 	}
 
-//	if (m_TurnNumber == 0)
-//		m_ComponentManager.GetScriptInterface().DumpHeap();
-
 	// Run the GC occasionally
 	// No delay because a lot of garbage accumulates in one turn and in non-visual replays there are
 	// much more turns in the same time than in normal games.
diff --git a/source/simulation2/components/CCmpAIManager.cpp b/source/simulation2/components/CCmpAIManager.cpp
index 90f4b7d5a9..2ec0cb7a8b 100644
--- a/source/simulation2/components/CCmpAIManager.cpp
+++ b/source/simulation2/components/CCmpAIManager.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2015 Wildfire Games.
+/* Copyright (C) 2016 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -221,7 +221,6 @@ public:
 
 		m_ScriptInterface->RegisterFunction<void, int, JS::HandleValue, CAIWorker::PostCommand>("PostCommand");
 		m_ScriptInterface->RegisterFunction<void, std::wstring, CAIWorker::IncludeModule>("IncludeModule");
-		m_ScriptInterface->RegisterFunction<void, CAIWorker::DumpHeap>("DumpHeap");
 		m_ScriptInterface->RegisterFunction<void, CAIWorker::ForceGC>("ForceGC");
 
 		m_ScriptInterface->RegisterFunction<JS::Value, JS::HandleValue, JS::HandleValue, pass_class_t, CAIWorker::ComputePath>("ComputePath");
@@ -333,11 +332,6 @@ public:
 		return retVal;
 	}
 
-	// The next two ought to be implmeneted someday but for now as it returns "null" it can't
-	static void DumpHeap(ScriptInterface::CxPrivate* pCxPrivate)
-	{
-		pCxPrivate->pScriptInterface->DumpHeap();
-	}
 	static void ForceGC(ScriptInterface::CxPrivate* pCxPrivate)
 	{
 		PROFILE3("AI compute GC");