diff --git a/debianutils/start_stop_daemon.c b/debianutils/start_stop_daemon.c
index d8a0d7d46..cf792709c 100644
--- a/debianutils/start_stop_daemon.c
+++ b/debianutils/start_stop_daemon.c
@@ -14,6 +14,8 @@
 #include <getopt.h>
 #include <sys/resource.h>
 
+/* Override ENABLE_FEATURE_PIDFILE */
+#define WANT_PIDFILE 1
 #include "libbb.h"
 
 static int signal_nr = 15;
@@ -46,7 +48,7 @@ static int pid_is_exec(pid_t pid, const char *name)
 	n = strcmp(execbuf, name);
 	if (ENABLE_FEATURE_CLEAN_UP)
 		free(execbuf);
-	return ~n; /* nonzero (true) if execbuf == name */
+	return !n; /* nonzero (true) if execbuf == name */
 }
 
 static int pid_is_user(int pid, int uid)
@@ -301,10 +303,14 @@ int start_stop_daemon_main(int argc, char **argv)
 		pid_t pid = vfork();
 		if (pid < 0) /* error */
 			bb_perror_msg_and_die("vfork");
-		if (pid == 0) /* parent */
-			return 0;
+		if (pid != 0) {
+			/* parent */
+			/* why _exit? the child may have changed the stack,
+			 * so "return 0" may do bad things */
+			_exit(0);
 		}
 		/* child */
+		setsid(); /* detach from controlling tty */
 		/* Redirect stdio to /dev/null, close extra FDs.
 		 * We do not actually daemonize because of DAEMON_ONLY_SANITIZE */
 		bb_daemonize_or_rexec(
@@ -316,11 +322,7 @@ int start_stop_daemon_main(int argc, char **argv)
 	}
 	if (opt & OPT_MAKEPID) {
 		/* user wants _us_ to make the pidfile */
-		FILE *pidf = xfopen(pidfile, "w");
-
-		pid_t pidt = getpid();
-		fprintf(pidf, "%d\n", pidt);
-		fclose(pidf);
+		write_pidfile(pidfile);
 	}
 	if (opt & OPT_c) {
 		struct bb_uidgid_t ugid;
diff --git a/include/libbb.h b/include/libbb.h
index 547b8f798..1cbcb41e4 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -619,8 +619,9 @@ llist_t *llist_rev(llist_t *list);
  *   llist_t *llist_add_to(llist_t *old_head, void *data)
  * etc does not result in smaller code... */
 
-
-#if ENABLE_FEATURE_PIDFILE
+/* start_stop_daemon and (udhcpc with ifupdown) are special - they want to
+ * create pidfiles regardless of FEATURE_PIDFILE. */
+#if ENABLE_FEATURE_PIDFILE || defined(WANT_PIDFILE)
 int write_pidfile(const char *path);
 #define remove_pidfile(f) ((void)unlink(f))
 #else
diff --git a/libbb/pidfile.c b/libbb/pidfile.c
index 79c3108fc..50af91f4e 100644
--- a/libbb/pidfile.c
+++ b/libbb/pidfile.c
@@ -6,9 +6,11 @@
  *
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
+
+/* Override ENABLE_FEATURE_PIDFILE */
+#define WANT_PIDFILE 1
 #include "libbb.h"
 
-#if ENABLE_FEATURE_PIDFILE
 int write_pidfile(const char *path)
 {
 	int pid_fd;
@@ -26,4 +28,3 @@ int write_pidfile(const char *path)
 	close(pid_fd);
 	return 1;
 }
-#endif
diff --git a/networking/ifupdown.c b/networking/ifupdown.c
index a15e1411e..040bbe389 100644
--- a/networking/ifupdown.c
+++ b/networking/ifupdown.c
@@ -536,8 +536,8 @@ static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)
 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 {
 	return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
-			"[[ --server %server%]][[ --hwaddr %hwaddr%]] "
-			"--returniffail --serverbcast", ifd, exec);
+			"[[ --server %server%]][[ --hwaddr %hwaddr%]]"
+			" --returniffail --serverbcast", ifd, exec);
 }
 
 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index b84a6785a..4bb90c2da 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -11,6 +11,8 @@
 #include <getopt.h>
 #include <syslog.h>
 
+/* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
+#define WANT_PIDFILE 1
 #include "common.h"
 #include "dhcpd.h"
 #include "dhcpc.h"