--- src/su.c.orig	2013-05-20
+++ src/su.c		2013-05-20
@@ -1076,7 +1076,7 @@ int main (int argc, char **argv)
 
 	set_environment (pw);
 
-	if (!doshell) {
+	if (!doshell && pw->pw_uid != 0) {
 		/* There is no need for a controlling terminal.
 		 * This avoids the callee to inject commands on
 		 * the caller's tty. */