diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index d3121a469f..ac4490c0b8 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -2144,6 +2144,7 @@ ExecGrant_generic(InternalGrant *istmt, Oid classid, AclMode default_privs)
 	{
 		Oid			objectid = lfirst_oid(cell);
 		Datum		aclDatum;
+		Datum		nameDatum;
 		bool		isNull;
 		AclMode		avail_goptions;
 		AclMode		this_privileges;
@@ -2197,6 +2198,11 @@ ExecGrant_generic(InternalGrant *istmt, Oid classid, AclMode default_privs)
 							old_acl, ownerId,
 							&grantorId, &avail_goptions);
 
+		nameDatum = SysCacheGetAttr(cacheid, tuple,
+									get_object_attnum_name(classid),
+									&isNull);
+		Assert(!isNull);
+
 		/*
 		 * Restrict the privileges to what we can actually grant, and emit the
 		 * standards-mandated warning and error messages.
@@ -2205,7 +2211,7 @@ ExecGrant_generic(InternalGrant *istmt, Oid classid, AclMode default_privs)
 			restrict_and_check_grant(istmt->is_grant, avail_goptions,
 									 istmt->all_privs, istmt->privileges,
 									 objectid, grantorId, get_object_type(classid, objectid),
-									 NameStr(*DatumGetName(SysCacheGetAttr(cacheid, tuple, get_object_attnum_name(classid), &isNull))),
+									 NameStr(*DatumGetName(nameDatum)),
 									 0, NULL);
 
 		/*