diff --git a/library/std/src/sys/solid/time.rs b/library/std/src/sys/solid/time.rs
index c67a736a9032c..ab988be24442a 100644
--- a/library/std/src/sys/solid/time.rs
+++ b/library/std/src/sys/solid/time.rs
@@ -21,7 +21,7 @@ impl SystemTime {
                 tm_min: rtc.tm_min,
                 tm_hour: rtc.tm_hour,
                 tm_mday: rtc.tm_mday,
-                tm_mon: rtc.tm_mon,
+                tm_mon: rtc.tm_mon - 1,
                 tm_year: rtc.tm_year,
                 tm_wday: rtc.tm_wday,
                 tm_yday: 0,