diff --git a/usr.bin/sed/compile.c b/usr.bin/sed/compile.c
index 2d7f8d2f6e73..b5bc3e26f40a 100644
--- a/usr.bin/sed/compile.c
+++ b/usr.bin/sed/compile.c
@@ -160,10 +160,10 @@ compile_stream(struct s_command **link)
 	char re[_POSIX2_LINE_MAX + 1];
 	int naddr;				/* Number of addresses */
 
-	stack = 0;
+	stack = NULL;
 	for (;;) {
 		if ((p = cu_fgets(lbuf, sizeof(lbuf), NULL)) == NULL) {
-			if (stack != 0)
+			if (stack != NULL)
 				errx(1, "%lu: %s: unexpected EOF (pending }'s)",
 							linenum, fname);
 			return (link);
@@ -203,9 +203,9 @@ semicolon:	EATSPACE();
 				p = compile_addr(p, cmd->a2);
 				EATSPACE();
 			} else
-				cmd->a2 = 0;
+				cmd->a2 = NULL;
 		} else
-			cmd->a1 = cmd->a2 = 0;
+			cmd->a1 = cmd->a2 = NULL;
 
 nonsel:		/* Now parse the command */
 		if (!*p)
@@ -241,7 +241,7 @@ semicolon:	EATSPACE();
 			 * group is really just a noop.
 			 */
 			cmd->nonsel = 1;
-			if (stack == 0)
+			if (stack == NULL)
 				errx(1, "%lu: %s: unexpected }", linenum, fname);
 			cmd2 = stack;
 			stack = cmd2->next;