diff --git a/src/modules/meson.build b/src/modules/meson.build
index abe8d76b8..2fc96d471 100644
--- a/src/modules/meson.build
+++ b/src/modules/meson.build
@@ -136,6 +136,7 @@ pipewire_module_protocol_pulse_sources = [
   'module-protocol-pulse/format.c',
   'module-protocol-pulse/manager.c',
   'module-protocol-pulse/pulse-server.c',
+  'module-protocol-pulse/volume.c',
   'module-protocol-pulse/modules/module-combine-sink.c',
   'module-protocol-pulse/modules/module-echo-cancel.c',
   'module-protocol-pulse/modules/module-ladspa-sink.c',
diff --git a/src/modules/module-protocol-pulse/collect.h b/src/modules/module-protocol-pulse/collect.h
index c0fa602e9..2405f0a8f 100644
--- a/src/modules/module-protocol-pulse/collect.h
+++ b/src/modules/module-protocol-pulse/collect.h
@@ -29,6 +29,9 @@
 #include "format.h"
 #include "volume.h"
 
+struct pw_manager;
+struct pw_manager_object;
+
 struct device_info {
 	uint32_t direction;
 
diff --git a/src/modules/module-protocol-pulse/internal.h b/src/modules/module-protocol-pulse/internal.h
index a688c9ae0..6b8ec2fd2 100644
--- a/src/modules/module-protocol-pulse/internal.h
+++ b/src/modules/module-protocol-pulse/internal.h
@@ -35,6 +35,7 @@
 #include <pipewire/private.h>
 
 #include "format.h"
+#include "volume.h"
 
 struct defs {
 	struct spa_fraction min_req;
@@ -123,15 +124,6 @@ struct buffer_attr {
 	uint32_t fragsize;
 };
 
-struct volume {
-	uint8_t channels;
-	float values[CHANNELS_MAX];
-};
-
-#define VOLUME_INIT	(struct volume) {		\
-				.channels = 0,		\
-			}
-
 struct stream {
 	uint32_t create_tag;
 	uint32_t channel;	/* index in map */
diff --git a/src/modules/module-protocol-pulse/pulse-server.c b/src/modules/module-protocol-pulse/pulse-server.c
index fc2b40fff..df9fc8422 100644
--- a/src/modules/module-protocol-pulse/pulse-server.c
+++ b/src/modules/module-protocol-pulse/pulse-server.c
@@ -84,6 +84,7 @@
 #include "defs.h"
 #include "format.h"
 #include "internal.h"
+#include "volume.h"
 
 #define DEFAULT_MIN_REQ		"256/48000"
 #define DEFAULT_DEFAULT_REQ	"960/48000"
@@ -99,7 +100,6 @@
 #define MAX_FORMATS	32
 #define MAX_CLIENTS	64
 
-#include "volume.c"
 #include "message.c"
 #include "manager.h"
 #include "dbus-name.c"
diff --git a/src/modules/module-protocol-pulse/volume.c b/src/modules/module-protocol-pulse/volume.c
index 4c3d4cc3a..94f90eb5f 100644
--- a/src/modules/module-protocol-pulse/volume.c
+++ b/src/modules/module-protocol-pulse/volume.c
@@ -22,24 +22,15 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include <spa/param/props.h>
+#include <spa/param/audio/raw.h>
+#include <spa/pod/iter.h>
+#include <spa/utils/defs.h>
+#include <pipewire/log.h>
+
 #include "volume.h"
 
-static inline bool volume_valid(const struct volume *vol)
-{
-	if (vol->channels == 0 || vol->channels > CHANNELS_MAX)
-		return false;
-	return true;
-}
-
-static inline void volume_make(struct volume *vol, uint8_t channels)
-{
-	uint8_t i;
-	for (i = 0; i < channels; i++)
-		vol->values[i] = 1.0f;
-	vol->channels = channels;
-}
-
-static inline int volume_compare(struct volume *vol, struct volume *other)
+int volume_compare(struct volume *vol, struct volume *other)
 {
 	uint8_t i;
 	if (vol->channels != other->channels) {
@@ -55,7 +46,7 @@ static inline int volume_compare(struct volume *vol, struct volume *other)
 	return 0;
 }
 
-static int volume_parse_param(const struct spa_pod *param, struct volume_info *info, bool monitor)
+int volume_parse_param(const struct spa_pod *param, struct volume_info *info, bool monitor)
 {
 	struct spa_pod_object *obj = (struct spa_pod_object *) param;
 	struct spa_pod_prop *prop;
@@ -66,7 +57,7 @@ static int volume_parse_param(const struct spa_pod *param, struct volume_info *i
 			if (spa_pod_get_float(&prop->value, &info->level) < 0)
 				continue;
 			SPA_FLAG_UPDATE(info->flags, VOLUME_HW_VOLUME,
-                                        prop->flags & SPA_POD_PROP_FLAG_HARDWARE);
+					prop->flags & SPA_POD_PROP_FLAG_HARDWARE);
 
 			break;
 		case SPA_PROP_mute:
@@ -75,7 +66,7 @@ static int volume_parse_param(const struct spa_pod *param, struct volume_info *i
 			if (spa_pod_get_bool(&prop->value, &info->mute) < 0)
 				continue;
 			SPA_FLAG_UPDATE(info->flags, VOLUME_HW_MUTE,
-                                        prop->flags & SPA_POD_PROP_FLAG_HARDWARE);
+					prop->flags & SPA_POD_PROP_FLAG_HARDWARE);
 			break;
 		case SPA_PROP_channelVolumes:
 			if (monitor)
@@ -83,7 +74,7 @@ static int volume_parse_param(const struct spa_pod *param, struct volume_info *i
 			info->volume.channels = spa_pod_copy_array(&prop->value, SPA_TYPE_Float,
 					info->volume.values, SPA_AUDIO_MAX_CHANNELS);
 			SPA_FLAG_UPDATE(info->flags, VOLUME_HW_VOLUME,
-                                        prop->flags & SPA_POD_PROP_FLAG_HARDWARE);
+					prop->flags & SPA_POD_PROP_FLAG_HARDWARE);
 			break;
 		case SPA_PROP_monitorMute:
 			if (!monitor)
diff --git a/src/modules/module-protocol-pulse/volume.h b/src/modules/module-protocol-pulse/volume.h
index 95567fda6..11ec51a77 100644
--- a/src/modules/module-protocol-pulse/volume.h
+++ b/src/modules/module-protocol-pulse/volume.h
@@ -26,7 +26,22 @@
 #ifndef PULSE_SERVER_VOLUME_H
 #define PULSE_SERVER_VOLUME_H
 
-#include "internal.h"
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "format.h"
+
+struct spa_pod;
+
+struct volume {
+	uint8_t channels;
+	float values[CHANNELS_MAX];
+};
+
+#define VOLUME_INIT		\
+	(struct volume) {	\
+		.channels = 0,	\
+	}
 
 struct volume_info {
 	struct volume volume;
@@ -40,12 +55,31 @@ struct volume_info {
 	uint32_t flags;
 };
 
-#define VOLUME_INFO_INIT	(struct volume_info) {		\
-					.volume = VOLUME_INIT,	\
-					.mute = false,		\
-					.level = 1.0,		\
-					.base = 1.0,		\
-					.steps = 256,		\
-				}
+#define VOLUME_INFO_INIT		\
+	(struct volume_info) {		\
+		.volume = VOLUME_INIT,	\
+		.mute = false,		\
+		.level = 1.0,		\
+		.base = 1.0,		\
+		.steps = 256,		\
+	}
+
+static inline bool volume_valid(const struct volume *vol)
+{
+	if (vol->channels == 0 || vol->channels > CHANNELS_MAX)
+		return false;
+	return true;
+}
+
+static inline void volume_make(struct volume *vol, uint8_t channels)
+{
+	uint8_t i;
+	for (i = 0; i < channels; i++)
+		vol->values[i] = 1.0f;
+	vol->channels = channels;
+}
+
+int volume_compare(struct volume *vol, struct volume *other);
+int volume_parse_param(const struct spa_pod *param, struct volume_info *info, bool monitor);
 
 #endif