diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 6ff48bb18f3639ae45d9528b32df51a4aebc60c0..0a22cace11d9df6b5fc085bfd7b86319f4b13165 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -851,6 +851,12 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 					 parser_errposition(pstate, defel->location)));
 	}
 
+	if (dlocale && (dcollate || dctype))
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("conflicting or redundant options"),
+				 errdetail("LOCALE cannot be specified together with LC_COLLATE or LC_CTYPE.")));
+
 	if (downer && downer->arg)
 		dbowner = defGetString(downer);
 	if (dtemplate && dtemplate->arg)