diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index a7953f3..4b3fbff 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -856,13 +856,6 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
 	return true;
 }
 
-#ifdef FRONTEND
-/*
- * Functions that are currently not needed in the backend, but are better
- * implemented inside xlogreader.c because of the internal facilities available
- * here.
- */
-
 /*
  * Find the first record with an lsn >= RecPtr.
  *
@@ -981,9 +974,6 @@ out:
 	return found;
 }
 
-#endif							/* FRONTEND */
-
-
 /* ----------------------------------------
  * Functions for decoding the data and block references in a record.
  * ----------------------------------------
diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c
index d9e1026..4199f6d 100644
--- a/src/backend/replication/slotfuncs.c
+++ b/src/backend/replication/slotfuncs.c
@@ -357,6 +357,9 @@ pg_logical_replication_slot_advance(XLogRecPtr startlsn, XLogRecPtr moveto)
 		CurrentResourceOwner = ResourceOwnerCreate(CurrentResourceOwner,
 												   "logical decoding");
 
+		/* Move to the first valid record with an lsn >= startlsn */
+		startlsn = XLogFindNextRecord(ctx->reader, startlsn);
+
 		/* invalidate non-timetravel entries */
 		InvalidateSystemCaches();
 
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index f307b63..7df5a80 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -211,10 +211,7 @@ extern bool XLogReaderValidatePageHeader(XLogReaderState *state,
 
 /* Invalidate read state */
 extern void XLogReaderInvalReadState(XLogReaderState *state);
-
-#ifdef FRONTEND
 extern XLogRecPtr XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr);
-#endif							/* FRONTEND */
 
 /* Functions for decoding an XLogRecord */