diff --git a/repos/os/include/audio_in_session/audio_in_session.h b/repos/os/include/audio_in_session/audio_in_session.h
index 75c1ffbf5b..fd37fa3282 100644
--- a/repos/os/include/audio_in_session/audio_in_session.h
+++ b/repos/os/include/audio_in_session/audio_in_session.h
@@ -36,10 +36,14 @@ namespace Audio_in {
 
 	enum {
 		QUEUE_SIZE  = 431,            /* buffer queue size (~5s) */
-		PERIOD      = 512,            /* samples per periode (~11.6ms) */
 		SAMPLE_RATE = 44100,
 		SAMPLE_SIZE = sizeof(float),
 	};
+
+	/**
+	 * Samples per period (~11.6ms)
+	 */
+	static constexpr Genode::size_t PERIOD = 512;
 }
 
 
@@ -265,7 +269,7 @@ class Audio_in::Session : public Genode::Session
 {
 	protected:
 
-		Stream *_stream;
+		Stream *_stream { nullptr };
 
 	public:
 
diff --git a/repos/os/include/audio_in_session/client.h b/repos/os/include/audio_in_session/client.h
index 46624b97c7..da3822b243 100644
--- a/repos/os/include/audio_in_session/client.h
+++ b/repos/os/include/audio_in_session/client.h
@@ -29,8 +29,8 @@ namespace Audio_in {
 
 struct Audio_in::Signal
 {
-	Genode::Signal_receiver           recv;
-	Genode::Signal_context            context;
+	Genode::Signal_receiver           recv    { };
+	Genode::Signal_context            context { };
 	Genode::Signal_context_capability cap;
 
 	Signal() : cap(recv.manage(&context)) { }
@@ -46,7 +46,7 @@ class Audio_in::Session_client : public Genode::Rpc_client<Session>
 
 		Genode::Attached_dataspace _shared_ds;
 
-		Signal _progress;
+		Signal _progress { };
 
 		Genode::Signal_transmitter _data_avail;
 
@@ -77,13 +77,13 @@ class Audio_in::Session_client : public Genode::Rpc_client<Session>
 		 ** Signals **
 		 *************/
 
-		void progress_sigh(Genode::Signal_context_capability sigh) {
+		void progress_sigh(Genode::Signal_context_capability sigh) override {
 			call<Rpc_progress_sigh>(sigh); }
 
-		void overrun_sigh(Genode::Signal_context_capability sigh) {
+		void overrun_sigh(Genode::Signal_context_capability sigh) override {
 			call<Rpc_overrun_sigh>(sigh); }
 
-		Genode::Signal_context_capability data_avail_sigh() {
+		Genode::Signal_context_capability data_avail_sigh() override {
 			return Genode::Signal_context_capability(); }
 
 
@@ -91,7 +91,7 @@ class Audio_in::Session_client : public Genode::Rpc_client<Session>
 		 ** Session interface **
 		 ***********************/
 
-		void start()
+		void start() override
 		{
 			call<Rpc_start>();
 
@@ -99,7 +99,7 @@ class Audio_in::Session_client : public Genode::Rpc_client<Session>
 			stream()->reset();
 		}
 
-		void stop() { call<Rpc_stop>();  }
+		void stop() override { call<Rpc_stop>(); }
 
 
 		/**********************************