diff --git a/src/common/backend/parser/gram.y b/src/common/backend/parser/gram.y
index 79fd7ef4e47be9e3f96743adbaa40b55c0d4fe8b..eb863a0b17d3349253a445eeadb092087916e297 100644
--- a/src/common/backend/parser/gram.y
+++ b/src/common/backend/parser/gram.y
@@ -25799,5 +25799,6 @@ static void RemoveFillerCol(List *filler_list, List *col_list)
 #undef yyerror
 #undef yylval
 #undef yylloc
+#undef yylex
 
 #include "scan.inc"
diff --git a/src/gausskernel/storage/replication/repl_gram.y b/src/gausskernel/storage/replication/repl_gram.y
index b38cc7e1507d91e137d68c4c3f3b8cf018dff9f4..1c65c3cffffac40f9216fc2f6acedb4b44fdd1aa 100755
--- a/src/gausskernel/storage/replication/repl_gram.y
+++ b/src/gausskernel/storage/replication/repl_gram.y
@@ -445,4 +445,6 @@ replication_yylex(YYSTYPE *lvalp, YYLTYPE *llocp,
 	return replication_scanner_yylex(&(lvalp->yy_core), llocp, yyscanner);
 }
 
+#undef yylex
+
 #include "repl_scanner.inc"
diff --git a/src/gausskernel/storage/replication/syncrep_gram.y b/src/gausskernel/storage/replication/syncrep_gram.y
index e435f4ef2d5a3e2f13fa481e3621889d4f0718d5..9f082cafac4da030d73535219a656f9ce47984cf 100644
--- a/src/gausskernel/storage/replication/syncrep_gram.y
+++ b/src/gausskernel/storage/replication/syncrep_gram.y
@@ -170,5 +170,6 @@ create_syncrep_config(const char *num_sync, List *members, uint8 syncrep_method)
 #undef yyerror
 #undef yylval
 #undef yylloc
+#undef yylex
 
 #include "syncrep_scanner.inc"