diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..1c96d17
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+us
diff --git a/makefile b/makefile
index ec6f2ab..84a0c0f 100644
--- a/makefile
+++ b/makefile
@@ -1,7 +1,7 @@
 CC ?= gcc
 CFLAGS = -Wall -pedantic --std=c99 -O2
 DBG_CFLAGS = -Wall -Werror -pedantic --std=c99 -O0 -g
-LDFLAGS = -lcrypt
+LDFLAGS != if [ "$(uname)" = 'Linux' ]; then printf '-lcrypt'; fi
 PREFIX = /usr/local
 MANPREFIX = ${PREFIX}/share/man
 
@@ -13,7 +13,7 @@ dbg:
 install: us
 	mkdir -p ${DESTDIR}${PREFIX}/bin
 	cp -f us ${DESTDIR}${PREFIX}/bin/us
-	chown root:root ${DESTDIR}${PREFIX}/bin/us
+	chown 0:0 ${DESTDIR}${PREFIX}/bin/us
 	chmod 4755 ${DESTDIR}${PREFIX}/bin/us
 #	mkdir -p ${DESTDIR}${MANPREFIX}/man1
 #	cp -f us.1 ${DESTDIR}${MANPREFIX}/man1/us.1
diff --git a/us.c b/us.c
index a888a87..4b486cc 100644
--- a/us.c
+++ b/us.c
@@ -17,7 +17,11 @@
 */
 
 #define _POSIX_C_SOURCE 200809L
+#ifdef __linux__
 #define _DEFAULT_SOURCE
+#else
+#define _BSD_SOURCE
+#endif
 
 #include <sys/types.h>
 #include <sys/wait.h>
@@ -298,7 +302,6 @@ static int authenticate(uid_t uid, char ask)
 		if (!op)
 			die("getpwuid_shadow:");
 		hash_p = op->pw_passwd;
-		exit(EXIT_FAILURE);
 #endif
 	} else {
 		hash_p = pw->pw_passwd;
@@ -374,7 +377,7 @@ static int authenticate(uid_t uid, char ask)
 
 	char *enc = crypt(pass, hash);
 	memset(pass, 0, 1024);
-	if (strcmp(enc, hash)) {
+	if (strncmp(hash, enc, 1024)) {
 		printf("Authentication failure\n");
 		setuid(uid);
 		return -1;