diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 63a34760ee..ab71b85dce 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -1965,8 +1965,9 @@ ExecConstraints(ResultRelInfo *resultRelInfo,
 
 				ereport(ERROR,
 						(errcode(ERRCODE_NOT_NULL_VIOLATION),
-						 errmsg("null value in column \"%s\" violates not-null constraint",
-								NameStr(att->attname)),
+						 errmsg("null value in column \"%s\" of relation \"%s\" violates not-null constraint",
+								NameStr(att->attname),
+								RelationGetRelationName(orig_rel)),
 						 val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
 						 errtablecol(orig_rel, attrChk)));
 			}