diff --git a/src/backend/parser/parse_coerce.c b/src/backend/parser/parse_coerce.c
index 6cab20d09a..1b11cf731c 100644
--- a/src/backend/parser/parse_coerce.c
+++ b/src/backend/parser/parse_coerce.c
@@ -25,6 +25,7 @@
 #include "parser/parse_relation.h"
 #include "parser/parse_type.h"
 #include "utils/builtins.h"
+#include "utils/datum.h"		/* needed for datumIsEqual() */
 #include "utils/lsyscache.h"
 #include "utils/syscache.h"
 #include "utils/typcache.h"