diff --git a/src/backend/commands/amcmds.c b/src/backend/commands/amcmds.c
index 188109e474c..72e209a8b01 100644
--- a/src/backend/commands/amcmds.c
+++ b/src/backend/commands/amcmds.c
@@ -53,7 +53,7 @@ CreateAccessMethod(CreateAmStmt *stmt)
 
 	rel = table_open(AccessMethodRelationId, RowExclusiveLock);
 
-	/* Must be super user */
+	/* Must be superuser */
 	if (!superuser())
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
diff --git a/src/backend/commands/foreigncmds.c b/src/backend/commands/foreigncmds.c
index 9b71beb1d38..146fa5733fc 100644
--- a/src/backend/commands/foreigncmds.c
+++ b/src/backend/commands/foreigncmds.c
@@ -573,7 +573,7 @@ CreateForeignDataWrapper(ParseState *pstate, CreateFdwStmt *stmt)
 
 	rel = table_open(ForeignDataWrapperRelationId, RowExclusiveLock);
 
-	/* Must be super user */
+	/* Must be superuser */
 	if (!superuser())
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
@@ -690,7 +690,7 @@ AlterForeignDataWrapper(ParseState *pstate, AlterFdwStmt *stmt)
 
 	rel = table_open(ForeignDataWrapperRelationId, RowExclusiveLock);
 
-	/* Must be super user */
+	/* Must be superuser */
 	if (!superuser())
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
diff --git a/src/backend/commands/tablespace.c b/src/backend/commands/tablespace.c
index 932e7ae37bc..4b96eec9dfe 100644
--- a/src/backend/commands/tablespace.c
+++ b/src/backend/commands/tablespace.c
@@ -242,7 +242,7 @@ CreateTableSpace(CreateTableSpaceStmt *stmt)
 	Oid			ownerId;
 	Datum		newOptions;
 
-	/* Must be super user */
+	/* Must be superuser */
 	if (!superuser())
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
diff --git a/src/test/regress/expected/conversion.out b/src/test/regress/expected/conversion.out
index 04fdcba4964..5c9d6317556 100644
--- a/src/test/regress/expected/conversion.out
+++ b/src/test/regress/expected/conversion.out
@@ -33,7 +33,7 @@ DROP CONVERSION mydef;
 -- so there's no need to do that here.
 --
 --
--- return to the super user
+-- return to the superuser
 --
 RESET SESSION AUTHORIZATION;
 DROP USER regress_conversion_user;
diff --git a/src/test/regress/sql/conversion.sql b/src/test/regress/sql/conversion.sql
index 83586824321..5576999e42e 100644
--- a/src/test/regress/sql/conversion.sql
+++ b/src/test/regress/sql/conversion.sql
@@ -30,7 +30,7 @@ DROP CONVERSION mydef;
 -- so there's no need to do that here.
 --
 --
--- return to the super user
+-- return to the superuser
 --
 RESET SESSION AUTHORIZATION;
 DROP USER regress_conversion_user;