diff --git a/source/vibe/core/concurrency.d b/source/vibe/core/concurrency.d
index 60a7dd4..05b4c42 100644
--- a/source/vibe/core/concurrency.d
+++ b/source/vibe/core/concurrency.d
@@ -1143,7 +1143,7 @@ Future!(ReturnType!CALLABLE) async(CALLABLE, ARGS...)(CALLABLE callable, ARGS ar
 	Future!RET ret;
 	ret.init();
 	static void compute(FreeListRef!(shared(RET)) dst, CALLABLE callable, ARGS args) {
-		dst = cast(shared(RET))callable(args);
+		dst.get = cast(shared(RET))callable(args);
 	}
 	static if (isWeaklyIsolated!CALLABLE && isWeaklyIsolated!ARGS) {
 		ret.m_task = runWorkerTaskH(&compute, ret.m_result, callable, args);
diff --git a/source/vibe/internal/freelistref.d b/source/vibe/internal/freelistref.d
index 216e3f3..5820da9 100644
--- a/source/vibe/internal/freelistref.d
+++ b/source/vibe/internal/freelistref.d
@@ -133,6 +133,8 @@ struct FreeListRef(T, bool INIT = true)
 		}
 	}
 
+	bool opCast(T)() const if (is(T == bool)) { return m_object !is null; }
+
 	void opAssign(FreeListRef other)
 	{
 		clear();
@@ -159,7 +161,6 @@ struct FreeListRef(T, bool INIT = true)
 		@property inout(T) get() inout @safe nothrow { return m_object; }
 	} else {
 		@property ref inout(T) get() inout @safe nothrow { return *m_object; }
-		void opAssign(T t) { *m_object = t; }
 	}
 	alias get this;