diff --git a/pgxn/neon/control_plane_connector.c b/pgxn/neon/control_plane_connector.c
index 00a582d718..93252e6b29 100644
--- a/pgxn/neon/control_plane_connector.c
+++ b/pgxn/neon/control_plane_connector.c
@@ -35,6 +35,7 @@
 #include "utils/memutils.h"
 #include "utils/jsonb.h"
 
+#include "control_plane_connector.h"
 #include "neon_utils.h"
 
 static ProcessUtility_hook_type PreviousProcessUtilityHook = NULL;
@@ -113,6 +114,8 @@ ConstructDeltaMessage()
 	if (RootTable.db_table)
 	{
 		JsonbValue	dbs;
+		HASH_SEQ_STATUS status;
+		DbEntry    *entry;
 
 		dbs.type = jbvString;
 		dbs.val.string.val = "dbs";
@@ -120,9 +123,6 @@ ConstructDeltaMessage()
 		pushJsonbValue(&state, WJB_KEY, &dbs);
 		pushJsonbValue(&state, WJB_BEGIN_ARRAY, NULL);
 
-		HASH_SEQ_STATUS status;
-		DbEntry    *entry;
-
 		hash_seq_init(&status, RootTable.db_table);
 		while ((entry = hash_seq_search(&status)) != NULL)
 		{
@@ -168,8 +168,9 @@ ConstructDeltaMessage()
 #else
 				const char *logdetail;
 #endif
+				char	   *encrypted_password;
 				PushKeyValue(&state, "password", (char *) entry->password);
-				char	   *encrypted_password = get_role_password(entry->name, &logdetail);
+				encrypted_password = get_role_password(entry->name, &logdetail);
 
 				if (encrypted_password)
 				{
@@ -831,7 +832,7 @@ NeonProcessUtility(
 	}
 }
 
-extern void
+void
 InitControlPlaneConnector()
 {
 	PreviousProcessUtilityHook = ProcessUtility_hook;
diff --git a/pgxn/neon/control_plane_connector.h b/pgxn/neon/control_plane_connector.h
index 12d6a97562..7eed449200 100644
--- a/pgxn/neon/control_plane_connector.h
+++ b/pgxn/neon/control_plane_connector.h
@@ -1,6 +1,6 @@
 #ifndef CONTROL_PLANE_CONNECTOR_H
 #define CONTROL_PLANE_CONNECTOR_H
 
-void		InitControlPlaneConnector();
+void		InitControlPlaneConnector(void);
 
 #endif
diff --git a/pgxn/neon/extension_server.c b/pgxn/neon/extension_server.c
index 039405e2cd..1329e2d17b 100644
--- a/pgxn/neon/extension_server.c
+++ b/pgxn/neon/extension_server.c
@@ -14,6 +14,7 @@
 
 #include "utils/guc.h"
 
+#include "extension_server.h" 
 #include "neon_utils.h"
 
 static int	extension_server_port = 0;
diff --git a/pgxn/neon/extension_server.h b/pgxn/neon/extension_server.h
new file mode 100644
index 0000000000..3e67708b85
--- /dev/null
+++ b/pgxn/neon/extension_server.h
@@ -0,0 +1,17 @@
+/*-------------------------------------------------------------------------
+ *
+ * extension_server.h
+ *	  Request compute_ctl to download extension files.
+ *
+ * IDENTIFICATION
+ *	 contrib/neon/extension_server.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef EXTENSION_SERVER_H
+#define EXTENSION_SERVER_H
+
+void pg_init_extension_server(void);
+
+#endif							/* EXTENSION_SERVER_H */
diff --git a/pgxn/neon/neon.c b/pgxn/neon/neon.c
index a14288b33a..1f456d9a3f 100644
--- a/pgxn/neon/neon.c
+++ b/pgxn/neon/neon.c
@@ -29,6 +29,7 @@
 #include "utils/guc.h"
 #include "utils/wait_event.h"
 
+#include "extension_server.h"
 #include "neon.h"
 #include "walproposer.h"
 #include "pagestore_client.h"
diff --git a/pgxn/neon/neon.h b/pgxn/neon/neon.h
index c3afecc679..a0f8c97497 100644
--- a/pgxn/neon/neon.h
+++ b/pgxn/neon/neon.h
@@ -25,12 +25,11 @@ extern int	wal_acceptor_connection_timeout;
 extern void pg_init_libpagestore(void);
 extern void pg_init_walproposer(void);
 
-extern void pg_init_extension_server(void);
-
 extern uint64 BackpressureThrottlingTime(void);
 extern void replication_feedback_get_lsns(XLogRecPtr *writeLsn, XLogRecPtr *flushLsn, XLogRecPtr *applyLsn);
 
 extern void PGDLLEXPORT WalProposerSync(int argc, char *argv[]);
 extern void PGDLLEXPORT WalProposerMain(Datum main_arg);
+PGDLLEXPORT void LogicalSlotsMonitorMain(Datum main_arg);
 
 #endif							/* NEON_H */
diff --git a/pgxn/neon/neon_utils.c b/pgxn/neon/neon_utils.c
index ce554c89df..1fb4ed9522 100644
--- a/pgxn/neon/neon_utils.c
+++ b/pgxn/neon/neon_utils.c
@@ -6,6 +6,7 @@
 
 #include "postgres.h"
 
+#include "neon_utils.h"
 #include "lib/stringinfo.h"
 #include "libpq/pqformat.h"
 
@@ -14,7 +15,7 @@
  *
  * Returns -1 if the character is not a hexadecimal digit.
  */
-int
+static int
 HexDecodeChar(char c)
 {
 	if (c >= '0' && c <= '9')
diff --git a/pgxn/neon/neon_utils.h b/pgxn/neon/neon_utils.h
index 10d41db102..89683714f1 100644
--- a/pgxn/neon/neon_utils.h
+++ b/pgxn/neon/neon_utils.h
@@ -12,7 +12,7 @@ uint32		pq_getmsgint32_le(StringInfo msg);
 uint64		pq_getmsgint64_le(StringInfo msg);
 void		pq_sendint32_le(StringInfo buf, uint32 i);
 void		pq_sendint64_le(StringInfo buf, uint64 i);
-extern void disable_core_dump();
+void        disable_core_dump(void);
 
 #ifndef WALPROPOSER_LIB
 
diff --git a/pgxn/neon/walproposer.c b/pgxn/neon/walproposer.c
index 0d5007ef73..10487636ae 100644
--- a/pgxn/neon/walproposer.c
+++ b/pgxn/neon/walproposer.c
@@ -1460,7 +1460,7 @@ RecvAppendResponses(Safekeeper *sk)
 }
 
 /* Parse a PageserverFeedback message, or the PageserverFeedback part of an AppendResponse */
-void
+static void
 ParsePageserverFeedbackMessage(WalProposer *wp, StringInfo reply_message, PageserverFeedback *rf)
 {
 	uint8		nkeys;
@@ -1590,9 +1590,9 @@ GetAcknowledgedByQuorumWALPosition(WalProposer *wp)
 Safekeeper *
 GetDonor(WalProposer *wp, XLogRecPtr *donor_lsn)
 {
-	*donor_lsn = InvalidXLogRecPtr;
 	Safekeeper *donor = NULL;
 	int			i;
+	*donor_lsn = InvalidXLogRecPtr;
 
 	if (wp->n_votes < wp->quorum)
 	{
diff --git a/pgxn/neon/walproposer_pg.c b/pgxn/neon/walproposer_pg.c
index 61a2a54809..7f07913fa6 100644
--- a/pgxn/neon/walproposer_pg.c
+++ b/pgxn/neon/walproposer_pg.c
@@ -398,7 +398,7 @@ walprop_pg_get_shmem_state(WalProposer *wp)
 	return walprop_shared;
 }
 
-void
+static void
 replication_feedback_set(PageserverFeedback *rf)
 {
 	SpinLockAcquire(&walprop_shared->mutex);