diff --git a/contrib/cube/cubedata.h b/contrib/cube/cubedata.h
index 8bfcc6e99a2..006a6d2c8c4 100644
--- a/contrib/cube/cubedata.h
+++ b/contrib/cube/cubedata.h
@@ -62,6 +62,7 @@ typedef struct NDBOX
 /* for cubescan.l and cubeparse.y */
 /* All grammar constructs return strings */
 #define YYSTYPE char *
+#define YY_TYPEDEF_YY_SCANNER_T
 typedef void *yyscan_t;
 
 /* in cubescan.l */
diff --git a/contrib/seg/segdata.h b/contrib/seg/segdata.h
index 7bc7c83dca3..b55ff78880b 100644
--- a/contrib/seg/segdata.h
+++ b/contrib/seg/segdata.h
@@ -16,6 +16,7 @@ extern int	significant_digits(const char *s);
 
 /* for segscan.l and segparse.y */
 union YYSTYPE;
+#define YY_TYPEDEF_YY_SCANNER_T
 typedef void *yyscan_t;
 
 /* in segscan.l */
diff --git a/src/backend/utils/adt/jsonpath_internal.h b/src/backend/utils/adt/jsonpath_internal.h
index 71f885475dd..0d8b89abea2 100644
--- a/src/backend/utils/adt/jsonpath_internal.h
+++ b/src/backend/utils/adt/jsonpath_internal.h
@@ -22,6 +22,7 @@ typedef struct JsonPathString
 	int			total;
 } JsonPathString;
 
+#define YY_TYPEDEF_YY_SCANNER_T
 typedef void *yyscan_t;
 
 #include "utils/jsonpath.h"
diff --git a/src/include/bootstrap/bootstrap.h b/src/include/bootstrap/bootstrap.h
index ccec9415acb..782a2829c71 100644
--- a/src/include/bootstrap/bootstrap.h
+++ b/src/include/bootstrap/bootstrap.h
@@ -56,6 +56,7 @@ extern void boot_get_type_io_data(Oid typid,
 								  Oid *typoutput);
 
 union YYSTYPE;
+#define YY_TYPEDEF_YY_SCANNER_T
 typedef void *yyscan_t;
 
 extern int	boot_yyparse(yyscan_t yyscanner);
diff --git a/src/include/replication/syncrep.h b/src/include/replication/syncrep.h
index b4134dbc91d..3fe44a880cf 100644
--- a/src/include/replication/syncrep.h
+++ b/src/include/replication/syncrep.h
@@ -101,7 +101,10 @@ extern void SyncRepUpdateSyncStandbysDefined(void);
  * in syncrep_gram.y and syncrep_scanner.l
  */
 union YYSTYPE;
+#ifndef YY_TYPEDEF_YY_SCANNER_T
+#define YY_TYPEDEF_YY_SCANNER_T
 typedef void *yyscan_t;
+#endif
 extern int	syncrep_yyparse(yyscan_t yyscanner);
 extern int	syncrep_yylex(union YYSTYPE *yylval_param, yyscan_t yyscanner);
 extern void syncrep_yyerror(yyscan_t yyscanner, const char *str);
diff --git a/src/include/replication/walsender_private.h b/src/include/replication/walsender_private.h
index a82ce33c083..f487d3ad9e9 100644
--- a/src/include/replication/walsender_private.h
+++ b/src/include/replication/walsender_private.h
@@ -126,7 +126,10 @@ extern void WalSndSetState(WalSndState state);
  * repl_scanner.l
  */
 union YYSTYPE;
+#ifndef YY_TYPEDEF_YY_SCANNER_T
+#define YY_TYPEDEF_YY_SCANNER_T
 typedef void *yyscan_t;
+#endif
 extern int	replication_yyparse(yyscan_t yyscanner);
 extern int	replication_yylex(union YYSTYPE *yylval_param, yyscan_t yyscanner);
 extern void replication_yyerror(yyscan_t yyscanner, const char *message) pg_attribute_noreturn();