diff --git a/src/lime/_internal/backend/html5/HTML5Thread.hx b/src/lime/_internal/backend/html5/HTML5Thread.hx
index 507da16be..575e67a48 100644
--- a/src/lime/_internal/backend/html5/HTML5Thread.hx
+++ b/src/lime/_internal/backend/html5/HTML5Thread.hx
@@ -442,7 +442,7 @@ abstract Message(Dynamic) from Dynamic to Dynamic
 			// so, there's a good chance it has thousands or millions of fields,
 			// which could take entire seconds to process.
 			&& (object.byteLength == null || object.byteOffset == null
-				|| object.buffer == null || !Std.isOfType(object.buffer, lime.utils.ArrayBuffer));
+				|| object.buffer == null || !Std.isOfType(object.buffer, #if haxe4 js.lib.ArrayBuffer #else js.html.ArrayBuffer #end));
 	}
 	#end
 
diff --git a/src/lime/system/ThreadPool.hx b/src/lime/system/ThreadPool.hx
index 74e951740..c2094630b 100644
--- a/src/lime/system/ThreadPool.hx
+++ b/src/lime/system/ThreadPool.hx
@@ -222,11 +222,13 @@ class ThreadPool extends WorkOutput
 		}
 		__activeJobs.clear();
 
+		#if lime_threads
 		// Cancel idle threads if there are more than the minimum.
 		while (idleThreads > minThreads)
 		{
 			__idleThreads.pop().sendMessage(new ThreadEvent(EXIT, null));
 		}
+		#end
 
 		// Clear the job queue.
 		if (error != null)