--- a/lposix.c
+++ b/lposix.c
@@ -1016,6 +1016,29 @@
 }
 #endif
 
+/*
+ * XXX: GNU and BSD handle the forward declaration of crypt() in different
+ * and annoying ways (especially GNU). Declare it here just to make sure
+ * that it's there
+ */
+char *crypt(const char *, const char *);
+
+static int Pcrypt(lua_State *L)
+{
+	const char *str, *salt;
+	char *res;
+
+	str = luaL_checkstring(L, 1);
+	salt = luaL_checkstring(L, 2);
+	if (strlen(salt) < 2)
+		luaL_error(L, "not enough salt");
+
+	res = crypt(str, salt);
+	lua_pushstring(L, res);
+
+	return 1;
+}
+
 static const luaL_reg R[] =
 {
 	{"access",		Paccess},
@@ -1023,6 +1046,7 @@
 	{"chdir",		Pchdir},
 	{"chmod",		Pchmod},
 	{"chown",		Pchown},
+	{"crypt",		Pcrypt},
 	{"ctermid",		Pctermid},
 	{"dirname",		Pdirname},
 	{"dir",			Pdir},
--- a/Makefile
+++ b/Makefile
@@ -37,8 +37,10 @@
 OS=$(shell uname)
 ifeq ($(OS),Darwin)
   LDFLAGS_SHARED=-bundle -undefined dynamic_lookup
+  LIBS=
 else
   LDFLAGS_SHARED=-shared
+  LIBS=-lcrypt
 endif
 
 # targets
@@ -50,7 +52,7 @@
 	$(LUA) test.lua
 
 $T:	$(OBJS)
-	$(CC) $(LDFLAGS) -o $@ $(LDFLAGS_SHARED) $(OBJS)
+	$(CC) $(LDFLAGS) -o $@ $(LDFLAGS_SHARED) $(OBJS) $(LIBS)
 
 $(OBJS): modemuncher.c