diff --git a/src/filter/Observer.cxx b/src/filter/Observer.cxx
index a5ae69eac..4ebb7a582 100644
--- a/src/filter/Observer.cxx
+++ b/src/filter/Observer.cxx
@@ -80,7 +80,7 @@ public:
 		return filter->FilterPCM(src);
 	}
 
-	ConstBuffer<void> Flush() noexcept override {
+	ConstBuffer<void> Flush() override {
 		return filter->Flush();
 	}
 };