diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index e1c2639fde..7cd31cb6ab 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -1895,6 +1895,13 @@ postgresExecForeignUpdate(EState *estate,
 
 	MemoryContextReset(fmstate->temp_cxt);
 
+	/* ERROR if more than one row was updated on the remote end */
+	if (n_rows > 1)
+		ereport(ERROR,
+				(errcode (ERRCODE_FDW_ERROR), /* XXX */
+				 errmsg ("updated %d rows for a tuple identity on the remote end",
+						 n_rows)));
+
 	/* Return NULL if nothing was updated on the remote end */
 	return (n_rows > 0) ? slot : NULL;
 }