diff --git a/src/output/SharedPipeConsumer.hxx b/src/output/SharedPipeConsumer.hxx
index 7b2b56ec7..04d1de8b8 100644
--- a/src/output/SharedPipeConsumer.hxx
+++ b/src/output/SharedPipeConsumer.hxx
@@ -37,28 +37,28 @@ class SharedPipeConsumer {
 	bool consumed;
 
 public:
-	void Init(const MusicPipe &_pipe) {
+	constexpr void Init(const MusicPipe &_pipe) noexcept {
 		pipe = &_pipe;
 		chunk = nullptr;
 	}
 
-	const MusicPipe &GetPipe() {
+	constexpr const MusicPipe &GetPipe() noexcept {
 		assert(pipe != nullptr);
 
 		return *pipe;
 	}
 
-	bool IsInitial() const {
+	constexpr bool IsInitial() const noexcept {
 		return chunk == nullptr;
 	}
 
-	void Cancel() {
+	constexpr void Cancel() noexcept {
 		chunk = nullptr;
 	}
 
 	const MusicChunk *Get() noexcept;
 
-	void Consume([[maybe_unused]] const MusicChunk &_chunk) {
+	constexpr void Consume([[maybe_unused]] const MusicChunk &_chunk) noexcept {
 		assert(chunk != nullptr);
 		assert(chunk == &_chunk);
 
@@ -68,7 +68,7 @@ public:
 	[[gnu::pure]]
 	bool IsConsumed(const MusicChunk &_chunk) const noexcept;
 
-	void ClearTail([[maybe_unused]] const MusicChunk &_chunk) noexcept {
+	constexpr void ClearTail([[maybe_unused]] const MusicChunk &_chunk) noexcept {
 		assert(chunk == &_chunk);
 		assert(consumed);
 		chunk = nullptr;