diff --git a/src/backend/commands/statscmds.c b/src/backend/commands/statscmds.c
index f95cd15..d8aa318 100644
--- a/src/backend/commands/statscmds.c
+++ b/src/backend/commands/statscmds.c
@@ -181,7 +181,7 @@ CreateStatistics(CreateStatsStmt *stmt)
 	for (i = 1; i < numcols; i++)
 		if (attnums[i] == attnums[i - 1])
 			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					(errcode(ERRCODE_DUPLICATE_COLUMN),
 				  errmsg("duplicate column name in statistics definition")));
 
 	stxkeys = buildint2vector(attnums, numcols);