diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index 08cd3fb6aaad015e4645dfc17ca9546becbf2b77..79643175fd36197e0afdeb63728c8b9738747204 100644
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -267,11 +267,6 @@ extern bool has_redistributable_clause(RestrictInfo *restrictinfo);
  */
 extern List *remove_useless_joins(PlannerInfo *root, List *joinlist);
 
-/*
- * prototypes for plan/analyzejoins.c
- */
-extern List *remove_useless_joins(PlannerInfo *root, List *joinlist);
-
 /*
  * prototypes for plan/setrefs.c
  */