diff --git a/libminijail.c b/libminijail.c
index b170db0..0a429c9 100644
--- a/libminijail.c
+++ b/libminijail.c
@@ -97,6 +97,7 @@
 		int chroot:1;
 		int mount_tmp:1;
 		int do_init:1;
+		int pid_file:1;
 	} flags;
 	uid_t uid;
 	gid_t gid;
@@ -108,6 +109,7 @@
 	int filter_len;
 	int binding_count;
 	char *chrootdir;
+	char *pid_file_path;
 	char *uidmap;
 	char *gidmap;
 	struct sock_fprog *filter_prog;
@@ -127,6 +129,7 @@
 	j->flags.readonly = 0;
 	j->flags.pids = 0;
 	j->flags.do_init = 0;
+	j->flags.pid_file = 0;
 }
 
 /*
@@ -354,6 +357,15 @@
 	j->flags.mount_tmp = 1;
 }
 
+int API minijail_write_pid_file(struct minijail *j, const char *path)
+{
+	j->pid_file_path = strdup(path);
+	if (!j->pid_file_path)
+		return -ENOMEM;
+	j->flags.pid_file = 1;
+	return 0;
+}
+
 int API minijail_bind(struct minijail *j, const char *src, const char *dest,
 		      int writeable)
 {
@@ -732,6 +744,18 @@
 	return 0;
 }
 
+static void write_pid_file(const struct minijail *j)
+{
+	FILE *fp = fopen(j->pid_file_path, "w");
+
+	if (!fp)
+		pdie("failed to open '%s'", j->pid_file_path);
+	if (fprintf(fp, "%d\n", (int)j->initpid) < 0)
+		pdie("fprintf(%s)", j->pid_file_path);
+	if (fclose(fp))
+		pdie("fclose(%s)", j->pid_file_path);
+}
+
 void drop_ugid(const struct minijail *j)
 {
 	if (j->flags.usergroups) {
@@ -1264,6 +1288,9 @@
 
 		j->initpid = child_pid;
 
+		if (j->flags.pid_file)
+			write_pid_file(j);
+
 		if (j->flags.userns)
 			write_ugid_mappings(j, userns_pipe_fds);
 
@@ -1411,6 +1438,9 @@
 	if (child_pid > 0 ) {
 		j->initpid = child_pid;
 
+		if (j->flags.pid_file)
+			write_pid_file(j);
+
 		if (j->flags.userns)
 			write_ugid_mappings(j, userns_pipe_fds);