diff --git a/usr.sbin/pw/Makefile b/usr.sbin/pw/Makefile
index c265399730c7..87bb5f68e3d6 100644
--- a/usr.sbin/pw/Makefile
+++ b/usr.sbin/pw/Makefile
@@ -3,7 +3,7 @@
 PROG=	pw
 MAN=	pw.conf.5 pw.8
 SRCS=	pw.c pw_conf.c pw_user.c pw_group.c pw_log.c pw_nis.c pw_vpw.c \
-	grupd.c pwupd.c psdate.c bitmap.c cpdir.c rm_r.c
+	grupd.c pwupd.c psdate.c bitmap.c cpdir.c rm_r.c strtounum.c
 
 WARNS?=	3
 
diff --git a/usr.sbin/pw/pw.c b/usr.sbin/pw/pw.c
index c1d9cd32a708..88c83dbfa125 100644
--- a/usr.sbin/pw/pw.c
+++ b/usr.sbin/pw/pw.c
@@ -199,7 +199,7 @@ main(int argc, char *argv[])
 			cmdhelp(mode, which);
 		else if (which != -1 && mode != -1) {
 			if (strspn(argv[1], "0123456789") == strlen(argv[1])) {
-				id = strtonum(argv[1], 0, LONG_MAX, &errstr);
+				id = strtounum(argv[1], 0, UID_MAX, &errstr);
 				if (errstr != NULL)
 					errx(EX_USAGE, "Bad id '%s': %s",
 					    argv[1], errstr);
@@ -269,7 +269,7 @@ main(int argc, char *argv[])
 			}
 			if (strspn(optarg, "0123456789") != strlen(optarg))
 				errx(EX_USAGE, "-g expects a number");
-			id = strtonum(optarg, 0, GID_MAX, &errstr);
+			id = strtounum(optarg, 0, GID_MAX, &errstr);
 			if (errstr != NULL)
 				errx(EX_USAGE, "Bad id '%s': %s", optarg,
 				    errstr);
@@ -281,7 +281,7 @@ main(int argc, char *argv[])
 				addarg(&arglist, 'u', optarg);
 				break;
 			}
-			id = strtonum(optarg, 0, UID_MAX, &errstr);
+			id = strtounum(optarg, 0, UID_MAX, &errstr);
 			if (errstr != NULL)
 				errx(EX_USAGE, "Bad id '%s': %s", optarg,
 				    errstr);
diff --git a/usr.sbin/pw/pw.h b/usr.sbin/pw/pw.h
index ed3b7158e907..3ab3c74a9537 100644
--- a/usr.sbin/pw/pw.h
+++ b/usr.sbin/pw/pw.h
@@ -32,6 +32,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <stdarg.h>
+#include <inttypes.h>
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -101,3 +102,6 @@ char *pw_pwcrypt(char *password);
 
 extern const char *Modes[];
 extern const char *Which[];
+
+uintmax_t strtounum(const char *numstr, uintmax_t minval, uintmax_t maxval,
+    const char **errmsg);