diff --git a/src/output/Registry.cxx b/src/output/Registry.cxx
index fe5fadd42..e4ab67fc8 100644
--- a/src/output/Registry.cxx
+++ b/src/output/Registry.cxx
@@ -94,7 +94,7 @@ constexpr const AudioOutputPlugin *audio_output_plugins[] = {
 };
 
 const AudioOutputPlugin *
-GetAudioOutputPluginByName(const char *name)
+GetAudioOutputPluginByName(const char *name) noexcept
 {
 	audio_output_plugins_for_each(plugin)
 		if (StringIsEqual(plugin->name, name))
diff --git a/src/output/Registry.hxx b/src/output/Registry.hxx
index 66250acb1..8fd077bb3 100644
--- a/src/output/Registry.hxx
+++ b/src/output/Registry.hxx
@@ -8,8 +8,9 @@ struct AudioOutputPlugin;
 
 extern const AudioOutputPlugin *const audio_output_plugins[];
 
+[[gnu::pure]]
 const AudioOutputPlugin *
-GetAudioOutputPluginByName(const char *name);
+GetAudioOutputPluginByName(const char *name) noexcept;
 
 #define audio_output_plugins_for_each(plugin) \
 	for (const AudioOutputPlugin *plugin, \