diff --git a/ircd/s_newconf.c b/ircd/s_newconf.c
index 31fcc959..0ee96e3e 100644
--- a/ircd/s_newconf.c
+++ b/ircd/s_newconf.c
@@ -697,6 +697,8 @@ valid_temp_time(const char *p)
 			return -1;
 		if (endp == p)
 			return -1;
+		if (current < 0)
+			return -1;
 
 		switch (*endp) {
 		case '\0': /* No unit was given so send it back as minutes */
diff --git a/tests/misc.c b/tests/misc.c
index 4a0e7141..e588266e 100644
--- a/tests/misc.c
+++ b/tests/misc.c
@@ -42,11 +42,44 @@ static void valid_temp_time1(void)
 	is_int(52 * WEEK, t, MSG);
 }
 
+static void valid_temp_time_invalid(void)
+{
+	time_t t;
+	t = valid_temp_time("-2w");
+	is_int(-1, t, MSG);
+
+	t = valid_temp_time("hello");
+	is_int(-1, t, MSG);
+
+	t = valid_temp_time("m");
+	is_int(-1, t, MSG);
+
+	t = valid_temp_time("1w-1w");
+	is_int(-1, t, MSG);
+}
+
+static void valid_temp_time_overflow(void)
+{
+	time_t max_time = (uintmax_t) (~(time_t)0) >> 1;
+	char s[100];
+	time_t t;
+
+	snprintf(s, sizeof s, "%" PRIuMAX "m", (uintmax_t) max_time / 60 + 2);
+	t = valid_temp_time(s);
+	is_int(52 * WEEK, t, MSG);
+
+	snprintf(s, sizeof s, "%" PRIuMAX "m%" PRIuMAX "m", (uintmax_t) max_time / 60 - 1, (uintmax_t) max_time / 60 - 1);
+	t = valid_temp_time(s);
+	is_int(52 * WEEK, t, MSG);
+}
+
 int main(int argc, char *argv[])
 {
 	plan_lazy();
 
 	valid_temp_time1();
+	valid_temp_time_invalid();
+	valid_temp_time_overflow();
 
 	return 0;
 }