diff --git a/src/backend/replication/logical/proto.c b/src/backend/replication/logical/proto.c
index 2a1f983..130e15f 100644
--- a/src/backend/replication/logical/proto.c
+++ b/src/backend/replication/logical/proto.c
@@ -668,8 +668,7 @@ logicalrep_write_attrs(StringInfo out, Relation rel)
 	/* fetch bitmap of REPLICATION IDENTITY attributes */
 	replidentfull = (rel->rd_rel->relreplident == REPLICA_IDENTITY_FULL);
 	if (!replidentfull)
-		idattrs = RelationGetIndexAttrBitmap(rel,
-											 INDEX_ATTR_BITMAP_IDENTITY_KEY);
+		idattrs = RelationSetIdentityKeyBitmap(rel);
 
 	/* send the attributes */
 	for (i = 0; i < desc->natts; i++)
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 29702d6..218ab91 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -5206,6 +5206,104 @@ restart:
 	}
 }
 
+Bitmapset *
+RelationSetIdentityKeyBitmap(Relation relation)
+{
+	Bitmapset  *idindexattrs;	/* columns in the replica identity */
+	List	   *indexoidlist;
+	List	   *newindexoidlist;
+	Oid			relpkindex;
+	Oid			relreplindex;
+	ListCell   *l;
+	MemoryContext oldcxt;
+
+	/* Quick exit if we already computed the result. */
+	if (relation->rd_idattr != NULL)
+		return bms_copy(relation->rd_idattr);
+
+	/* Fast path if definitely no indexes */
+	if (!RelationGetForm(relation)->relhasindex)
+		return NULL;
+
+	/*
+	 * Get cached list of index OIDs. If we have to start over, we do so here.
+	 */
+restart:
+	indexoidlist = RelationGetIndexList(relation);
+
+	/* Fall out if no indexes (but relhasindex was set) */
+	if (indexoidlist == NIL)
+		return NULL;
+
+	/* Save some values to compare after building attributes */
+	relpkindex = relation->rd_pkindex;
+	relreplindex = relation->rd_replidindex;
+
+	/*
+	 * build attributes to idindexattrs.
+	 */
+	idindexattrs = NULL;
+	foreach(l, indexoidlist)
+	{
+		Oid			indexOid = lfirst_oid(l);
+		Relation	indexDesc;
+		int			i;
+		bool		isIDKey;	/* replica identity index */
+
+		indexDesc = RelationIdGetRelation(indexOid);
+
+		/* Is this index the configured (or default) replica identity? */
+		isIDKey = (indexOid == relreplindex);
+
+		/* Collect simple attribute references */
+		for (i = 0; i < indexDesc->rd_index->indnatts; i++)
+		{
+			int			attrnum = indexDesc->rd_index->indkey.values[i];
+
+			/* Romove non-key columns here. */
+			if (attrnum != 0)
+			{
+				if (isIDKey && i < indexDesc->rd_index->indnkeyatts)
+					idindexattrs = bms_add_member(idindexattrs,
+												  attrnum - FirstLowInvalidHeapAttributeNumber);
+			}
+		}
+		RelationClose(indexDesc);
+	}
+
+	/* Check if we need to redo */
+	newindexoidlist = RelationGetIndexList(relation);
+	if (equal(indexoidlist, newindexoidlist) &&
+		relpkindex == relation->rd_pkindex &&
+		relreplindex == relation->rd_replidindex)
+	{
+		/* Still the same index set, so proceed */
+		list_free(newindexoidlist);
+		list_free(indexoidlist);
+	}
+	else
+	{
+		/* Gotta do it over ... might as well not leak memory */
+		list_free(newindexoidlist);
+		list_free(indexoidlist);
+		bms_free(idindexattrs);
+
+		goto restart;
+	}
+
+	/* Don't leak the old values of these bitmaps, if any */
+	bms_free(relation->rd_idattr);
+	relation->rd_idattr = NULL;
+
+	/* Now save copies of the bitmaps in the relcache entry */
+	oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
+	relation->rd_idattr = bms_copy(idindexattrs);
+	MemoryContextSwitchTo(oldcxt);
+
+	/* We return our original working copy for caller to play with */
+	return idindexattrs;
+}
+
 /*
  * RelationGetExclusionInfo -- get info about index's exclusion constraint
  *
diff --git a/src/include/utils/relcache.h b/src/include/utils/relcache.h
index 2fcdf79..de49ecc 100644
--- a/src/include/utils/relcache.h
+++ b/src/include/utils/relcache.h
@@ -65,6 +65,8 @@ typedef enum IndexAttrBitmapKind
 extern Bitmapset *RelationGetIndexAttrBitmap(Relation relation,
 											 IndexAttrBitmapKind attrKind);
 
+extern Bitmapset *RelationSetIdentityKeyBitmap(Relation relation);
+
 extern void RelationGetExclusionInfo(Relation indexRelation,
 									 Oid **operators,
 									 Oid **procs,