diff --git a/exec/evil.c b/exec/evil.c
index d2e99307..43986ebb 100644
--- a/exec/evil.c
+++ b/exec/evil.c
@@ -76,7 +76,10 @@
 #include "sync.h"
 #include "evil.h"
 
-static void clm_sync_init (void);
+static void clm_sync_init (
+	const unsigned int *member_list,
+	size_t member_list_entries,
+	const struct memb_ring_id *ring_id);
 
 static int clm_sync_process (void);
 
@@ -98,7 +101,10 @@ static struct sync_callbacks clm_sync_operations = {
 
 static struct corosync_api_v1 *api = NULL;
 
-static void sync_dummy_init (void)
+static void sync_dummy_init (
+	const unsigned int *member_list,
+	size_t member_list_entries,
+	const struct memb_ring_id *ring_id)
 {
 }
 
@@ -329,7 +335,10 @@ static int clm_nodejoin_send (void)
 /*
  * This is a noop for this service
  */
-static void clm_sync_init (void)
+static void clm_sync_init (
+	const unsigned int *member_list,
+	size_t member_list_entries,
+	const struct memb_ring_id *ring_id)
 {
 	return;
 }
diff --git a/exec/sync.c b/exec/sync.c
index 805badbf..6b086d68 100644
--- a/exec/sync.c
+++ b/exec/sync.c
@@ -78,7 +78,7 @@ static struct sync_callbacks sync_callbacks;
 static int sync_processing = 0;
 
 static void (*sync_next_start) (
-	unsigned int *member_list,
+	const unsigned int *member_list,
 	size_t member_list_entries,
 	const struct memb_ring_id *ring_id);
 
@@ -176,7 +176,7 @@ static void sync_start_init (const struct memb_ring_id *ring_id)
 
 static void sync_service_init (struct memb_ring_id *ring_id)
 {
-	sync_callbacks.sync_init ();
+	sync_callbacks.sync_init (my_member_list, my_member_list_entries, ring_id);
 	totempg_callback_token_destroy (&sync_callback_token_handle);
 
 	/*
@@ -264,7 +264,7 @@ int sync_register (
 		struct sync_callbacks *callbacks),
 
 	void (*next_start) (
-		unsigned int *member_list,
+		const unsigned int *member_list,
 		size_t member_list_entries,
 		const struct memb_ring_id *ring_id))
 {
diff --git a/exec/sync.h b/exec/sync.h
index c57b8694..78c4ab67 100644
--- a/exec/sync.h
+++ b/exec/sync.h
@@ -40,7 +40,10 @@
 #include "totemsrp.h"
 
 struct sync_callbacks {
-	void (*sync_init) (void);
+	void (*sync_init) (
+		const unsigned int *member_list,
+		size_t member_list_entries,
+		const struct memb_ring_id *ring_id);
 	int (*sync_process) (void);
 	void (*sync_activate) (void);
 	void (*sync_abort) (void);
@@ -53,7 +56,7 @@ int sync_register (
 		struct sync_callbacks *callbacks),
 
 	void (*next_start) (
-		unsigned int *member_list,
+		const unsigned int *member_list,
 		size_t member_list_entries,
 		const struct memb_ring_id *ring_id));
 
diff --git a/exec/syncv2.c b/exec/syncv2.c
index 211a53a9..89db1cf3 100644
--- a/exec/syncv2.c
+++ b/exec/syncv2.c
@@ -80,7 +80,10 @@ enum sync_state {
 
 struct service_entry {
 	int service_id;
-	void (*sync_init) (void);
+	void (*sync_init) (
+		const unsigned int *member_list,
+		size_t member_list_entries,
+		const struct memb_ring_id *ring_id);
 	void (*sync_abort) (void);
 	int (*sync_process) (void);
 	void (*sync_activate) (void);
@@ -113,7 +116,11 @@ static int my_processing_idx = 0;
 
 static hdb_handle_t my_schedwrk_handle;
 
-static struct processor_entry my_processor_list[128];
+static struct processor_entry my_processor_list[PROCESSOR_COUNT_MAX];
+
+static unsigned int my_member_list[PROCESSOR_COUNT_MAX];
+
+static size_t my_member_list_entries = 0;
 
 static int my_processor_list_entries = 0;
 
@@ -123,7 +130,7 @@ static int my_service_list_entries = 0;
 
 static const struct memb_ring_id sync_ring_id;
 
-static struct service_entry my_initial_service_list[128];
+static struct service_entry my_initial_service_list[PROCESSOR_COUNT_MAX];
 
 static int my_initial_service_list_entries;
 
@@ -229,7 +236,10 @@ static void sync_barrier_handler (unsigned int nodeid, const void *msg)
 	}
 }
 
-static void dummy_sync_init (void)
+static void dummy_sync_init (
+	const unsigned int *member_list,
+	unsigned int member_list_entries,
+	const struct memb_ring_id *ring_id)
 {
 }
 
@@ -438,7 +448,8 @@ static int schedwrk_processor (const void *context)
 
 	if (my_service_list[my_processing_idx].state == INIT) {
 		my_service_list[my_processing_idx].state = PROCESS;
-		my_service_list[my_processing_idx].sync_init ();
+		my_service_list[my_processing_idx].sync_init (my_member_list, my_member_list_entries,
+			&my_ring_id);
 	}
 	if (my_service_list[my_processing_idx].state == PROCESS) {
 		my_service_list[my_processing_idx].state = PROCESS;
diff --git a/include/corosync/engine/coroapi.h b/include/corosync/engine/coroapi.h
index 0f104156..3601bab7 100644
--- a/include/corosync/engine/coroapi.h
+++ b/include/corosync/engine/coroapi.h
@@ -629,7 +629,10 @@ struct corosync_service_engine {
 		const unsigned int *joined_list, size_t joined_list_entries,
 		const struct memb_ring_id *ring_id);
 	enum cs_sync_mode sync_mode;
-	void (*sync_init) (void);
+	void (*sync_init) (
+		const unsigned int *member_list,
+		size_t member_list_entries,
+		const struct memb_ring_id *ring_id);
 	int (*sync_process) (void);
 	void (*sync_activate) (void);
 	void (*sync_abort) (void);
diff --git a/services/cpg.c b/services/cpg.c
index 46ae68e6..5c93586c 100644
--- a/services/cpg.c
+++ b/services/cpg.c
@@ -206,7 +206,11 @@ static int cpg_node_joinleave_send (unsigned int pid, const mar_cpg_name_t *grou
 
 static int cpg_exec_send_joinlist(void);
 
-static void cpg_sync_init (void);
+static void cpg_sync_init (
+	const unsigned int *member_list,
+	size_t member_list_entries,
+	const struct memb_ring_id *ring_id);
+
 static int  cpg_sync_process (void);
 static void cpg_sync_activate (void);
 static void cpg_sync_abort (void);
@@ -354,7 +358,10 @@ struct req_exec_cpg_downlist {
 
 static struct req_exec_cpg_downlist g_req_exec_cpg_downlist;
 
-static void cpg_sync_init (void)
+static void cpg_sync_init (
+	const unsigned int *member_list,
+	size_t member_list_entries,
+	const struct memb_ring_id *ring_id)
 {
 }