diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index fd144d783d9..ec3b374f6fa 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -1685,6 +1685,17 @@ RemoveRelations(DropStmt *drop)
 			continue;
 		}
 
+		/*
+		 * An explicitly selected replica identity must remain available until
+		 * the table's replica identity is changed.
+		 */
+		if (drop->removeType == OBJECT_INDEX && get_index_isreplident(relOid))
+			ereport(ERROR,
+					errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST),
+					errmsg("cannot drop index \"%s\" because it is used as replica identity",
+						   rel->relname),
+					errhint("Use ALTER TABLE ... REPLICA IDENTITY to change the table's replica identity first."));
+
 		/*
 		 * Decide if concurrent mode needs to be used here or not.  The
 		 * callback retrieved the rel's persistence for us.
diff --git a/src/test/regress/expected/replica_identity.out b/src/test/regress/expected/replica_identity.out
index 1560cd04125..bcfcf1a1b4b 100644
--- a/src/test/regress/expected/replica_identity.out
+++ b/src/test/regress/expected/replica_identity.out
@@ -133,6 +133,10 @@ SELECT count(*) FROM pg_index WHERE indrelid = 'test_replica_identity'::regclass
      1
 (1 row)
 
+-- An explicitly selected replica identity index cannot be dropped.
+DROP INDEX test_replica_identity_keyab_key;
+ERROR:  cannot drop index "test_replica_identity_keyab_key" because it is used as replica identity
+HINT:  Use ALTER TABLE ... REPLICA IDENTITY to change the table's replica identity first.
 ----
 -- Make sure non index cases work
 ----
@@ -143,6 +147,7 @@ SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
  d
 (1 row)
 
+DROP INDEX test_replica_identity_keyab_key;
 SELECT count(*) FROM pg_index WHERE indrelid = 'test_replica_identity'::regclass AND indisreplident;
  count 
 -------
@@ -169,7 +174,6 @@ Indexes:
     "test_replica_identity_expr" UNIQUE, btree (keya, keyb, (3))
     "test_replica_identity_hash" hash (nonkey)
     "test_replica_identity_keyab" btree (keya, keyb)
-    "test_replica_identity_keyab_key" UNIQUE, btree (keya, keyb)
     "test_replica_identity_nonkey" UNIQUE, btree (keya, nonkey)
     "test_replica_identity_partial" UNIQUE, btree (keya, keyb) WHERE keyb <> '3'::text
     "test_replica_identity_unique_defer" UNIQUE CONSTRAINT, btree (keya, keyb) DEFERRABLE
@@ -200,7 +204,6 @@ Indexes:
     "test_replica_identity_expr" UNIQUE, btree (keya, keyb, (3))
     "test_replica_identity_hash" hash (nonkey)
     "test_replica_identity_keyab" btree (keya, keyb)
-    "test_replica_identity_keyab_key" UNIQUE, btree (keya, keyb)
     "test_replica_identity_nonkey" UNIQUE, btree (keya, nonkey)
     "test_replica_identity_partial" UNIQUE, btree (keya, keyb) WHERE keyb <> '3'::text
     "test_replica_identity_unique_defer" UNIQUE CONSTRAINT, btree (keya, keyb) DEFERRABLE
diff --git a/src/test/regress/sql/replica_identity.sql b/src/test/regress/sql/replica_identity.sql
index 4ebb097f282..b8d29ca8fa5 100644
--- a/src/test/regress/sql/replica_identity.sql
+++ b/src/test/regress/sql/replica_identity.sql
@@ -65,11 +65,15 @@ SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
 \d test_replica_identity
 SELECT count(*) FROM pg_index WHERE indrelid = 'test_replica_identity'::regclass AND indisreplident;
 
+-- An explicitly selected replica identity index cannot be dropped.
+DROP INDEX test_replica_identity_keyab_key;
+
 ----
 -- Make sure non index cases work
 ----
 ALTER TABLE test_replica_identity REPLICA IDENTITY DEFAULT;
 SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+DROP INDEX test_replica_identity_keyab_key;
 SELECT count(*) FROM pg_index WHERE indrelid = 'test_replica_identity'::regclass AND indisreplident;
 
 ALTER TABLE test_replica_identity REPLICA IDENTITY FULL;