diff --git a/Makefile.am b/Makefile.am
index bc5e58f54..e93e3413f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -602,6 +602,7 @@ test_run_output_SOURCES = test/run_output.c \
 	src/output_init.c src/output_list.c \
 	$(ENCODER_SRC) \
 	src/mixer_api.c \
+	src/mixer_control.c \
 	$(MIXER_SRC) \
 	$(OUTPUT_SRC)
 
diff --git a/src/audio.c b/src/audio.c
index 1b0d3262d..d48558e46 100644
--- a/src/audio.c
+++ b/src/audio.c
@@ -23,7 +23,6 @@
 #include "output_internal.h"
 #include "output_plugin.h"
 #include "output_all.h"
-#include "mixer_api.h"
 #include "conf.h"
 
 #include <glib.h>
diff --git a/src/mixer_all.c b/src/mixer_all.c
index b4ac024b9..34b16c4b7 100644
--- a/src/mixer_all.c
+++ b/src/mixer_all.c
@@ -18,7 +18,7 @@
  */
 
 #include "mixer_all.h"
-#include "mixer_api.h"
+#include "mixer_control.h"
 #include "output_all.h"
 #include "output_plugin.h"
 #include "output_internal.h"
diff --git a/src/mixer_api.c b/src/mixer_api.c
index 8ec4f41bc..3c9f54e14 100644
--- a/src/mixer_api.c
+++ b/src/mixer_api.c
@@ -26,58 +26,3 @@
 
 #undef G_LOG_DOMAIN
 #define G_LOG_DOMAIN "mixer"
-
-static bool mixers_enabled = true;
-
-void mixer_disable_all(void)
-{
-	g_debug("mixer api is disabled\n");
-	mixers_enabled = false;
-}
-
-struct mixer *
-mixer_new(const struct mixer_plugin *plugin, const struct config_param *param)
-{
-	struct mixer *mixer;
-
-	//mixers are disabled (by using software volume)
-	if (!mixers_enabled) {
-		return NULL;
-	}
-	assert(plugin != NULL);
-
-	mixer = plugin->init(param);
-
-	assert(mixer == NULL || mixer->plugin == plugin);
-
-	return mixer;
-}
-
-void
-mixer_free(struct mixer *mixer)
-{
-	if (!mixer) {
-		return;
-	}
-	assert(mixer->plugin != NULL);
-
-	mixer->plugin->finish(mixer);
-}
-
-bool mixer_open(struct mixer *mixer)
-{
-	if (!mixer) {
-		return false;
-	}
-	assert(mixer->plugin != NULL);
-	return mixer->plugin->open(mixer);
-}
-
-void mixer_close(struct mixer *mixer)
-{
-	if (!mixer) {
-		return;
-	}
-	assert(mixer->plugin != NULL);
-	mixer->plugin->close(mixer);
-}
diff --git a/src/mixer_api.h b/src/mixer_api.h
index 22858821c..a02ab2dd5 100644
--- a/src/mixer_api.h
+++ b/src/mixer_api.h
@@ -40,27 +40,4 @@ mixer_init(struct mixer *mixer, const struct mixer_plugin *plugin)
 	mixer->plugin = plugin;
 }
 
-struct mixer *
-mixer_new(const struct mixer_plugin *plugin, const struct config_param *param);
-
-void
-mixer_free(struct mixer *mixer);
-
-bool mixer_open(struct mixer *mixer);
-void mixer_close(struct mixer *mixer);
-
-static inline int
-mixer_get_volume(struct mixer *mixer)
-{
-	return mixer->plugin->get_volume(mixer);
-}
-
-static inline bool
-mixer_set_volume(struct mixer *mixer, unsigned volume)
-{
-	return mixer->plugin->set_volume(mixer, volume);
-}
-
-void mixer_disable_all(void);
-
 #endif
diff --git a/src/mixer_control.c b/src/mixer_control.c
index 229c3683e..ba49e2ec4 100644
--- a/src/mixer_control.c
+++ b/src/mixer_control.c
@@ -20,4 +20,80 @@
 #include "mixer_control.h"
 #include "mixer_api.h"
 
+#include <glib.h>
+
 #include <assert.h>
+#include <stddef.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "mixer"
+
+static bool mixers_enabled = true;
+
+void
+mixer_disable_all(void)
+{
+	g_debug("mixer api is disabled");
+	mixers_enabled = false;
+}
+
+struct mixer *
+mixer_new(const struct mixer_plugin *plugin, const struct config_param *param)
+{
+	struct mixer *mixer;
+
+	//mixers are disabled (by using software volume)
+	if (!mixers_enabled) {
+		return NULL;
+	}
+	assert(plugin != NULL);
+
+	mixer = plugin->init(param);
+
+	assert(mixer == NULL || mixer->plugin == plugin);
+
+	return mixer;
+}
+
+void
+mixer_free(struct mixer *mixer)
+{
+	if (!mixer) {
+		return;
+	}
+	assert(mixer->plugin != NULL);
+
+	mixer->plugin->finish(mixer);
+}
+
+bool
+mixer_open(struct mixer *mixer)
+{
+	if (!mixer) {
+		return false;
+	}
+	assert(mixer->plugin != NULL);
+	return mixer->plugin->open(mixer);
+}
+
+void
+mixer_close(struct mixer *mixer)
+{
+	if (!mixer) {
+		return;
+	}
+	assert(mixer->plugin != NULL);
+	mixer->plugin->close(mixer);
+}
+
+int
+mixer_get_volume(struct mixer *mixer)
+{
+	return mixer->plugin->get_volume(mixer);
+}
+
+bool
+mixer_set_volume(struct mixer *mixer, unsigned volume)
+{
+	return mixer->plugin->set_volume(mixer, volume);
+}
diff --git a/src/mixer_control.h b/src/mixer_control.h
index 4f3a97dbc..b126d8c81 100644
--- a/src/mixer_control.h
+++ b/src/mixer_control.h
@@ -17,9 +17,39 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+/** \file
+ *
+ * Functions which manipulate a #mixer object.
+ */
+
 #ifndef MPD_MIXER_CONTROL_H
 #define MPD_MIXER_CONTROL_H
 
 #include <stdbool.h>
 
+struct mixer;
+struct mixer_plugin;
+struct config_param;
+
+void
+mixer_disable_all(void);
+
+struct mixer *
+mixer_new(const struct mixer_plugin *plugin, const struct config_param *param);
+
+void
+mixer_free(struct mixer *mixer);
+
+bool
+mixer_open(struct mixer *mixer);
+
+void
+mixer_close(struct mixer *mixer);
+
+int
+mixer_get_volume(struct mixer *mixer);
+
+bool
+mixer_set_volume(struct mixer *mixer, unsigned volume);
+
 #endif
diff --git a/src/output/alsa_plugin.c b/src/output/alsa_plugin.c
index ce7a737da..15728a10f 100644
--- a/src/output/alsa_plugin.c
+++ b/src/output/alsa_plugin.c
@@ -19,6 +19,7 @@
 
 #include "../output_api.h"
 #include "../mixer_api.h"
+#include "mixer_control.h"
 
 #include <glib.h>
 #include <alsa/asoundlib.h>
diff --git a/src/output/oss_plugin.c b/src/output/oss_plugin.c
index 399a29146..b3a2257b7 100644
--- a/src/output/oss_plugin.c
+++ b/src/output/oss_plugin.c
@@ -19,6 +19,7 @@
 
 #include "../output_api.h"
 #include "../mixer_api.h"
+#include "mixer_control.h"
 
 #include <glib.h>
 
diff --git a/src/output/pulse_plugin.c b/src/output/pulse_plugin.c
index 109ccd3b9..b62b431a5 100644
--- a/src/output/pulse_plugin.c
+++ b/src/output/pulse_plugin.c
@@ -19,6 +19,7 @@
 
 #include "../output_api.h"
 #include "../mixer_api.h"
+#include "mixer_control.h"
 
 #include <glib.h>
 #include <pulse/simple.h>
diff --git a/src/output_command.c b/src/output_command.c
index 48985f5f9..7f16a79d7 100644
--- a/src/output_command.c
+++ b/src/output_command.c
@@ -28,7 +28,7 @@
 #include "output_all.h"
 #include "output_internal.h"
 #include "output_plugin.h"
-#include "mixer_api.h"
+#include "mixer_control.h"
 #include "idle.h"
 
 bool
diff --git a/src/volume.c b/src/volume.c
index a7bae9627..e120df403 100644
--- a/src/volume.c
+++ b/src/volume.c
@@ -24,7 +24,7 @@
 #include "pcm_volume.h"
 #include "config.h"
 #include "output_all.h"
-#include "mixer_api.h"
+#include "mixer_control.h"
 #include "mixer_all.h"
 
 #include <glib.h>