diff --git a/energiatili-model/src/measurement.rs b/energiatili-model/src/measurement.rs
index 9763969..d403343 100644
--- a/energiatili-model/src/measurement.rs
+++ b/energiatili-model/src/measurement.rs
@@ -216,7 +216,7 @@ where
 }
 
 fn convert_timestamp(timestamp: i64) -> DateTime<Utc> {
-    let naive_date = NaiveDateTime::from_timestamp((timestamp / 1000) as i64, 0);
+    let naive_date = NaiveDateTime::from_timestamp_opt((timestamp / 1000) as i64, 0).expect("parse NaiveDateTime");
     let localtime = match Helsinki.from_local_datetime(&naive_date) {
         LocalResult::None => panic!("Couldn't convert local time"),
         LocalResult::Single(t) => t,
diff --git a/energiatili-model/src/utils.rs b/energiatili-model/src/utils.rs
index 21077f7..11e0adf 100644
--- a/energiatili-model/src/utils.rs
+++ b/energiatili-model/src/utils.rs
@@ -14,7 +14,7 @@ pub(crate) fn fix_new_date(buf: &str) -> String {
 
             // Javascript's "new Date()" supposed to be seconds since UNIX epoch UTC,
             // but it seems Energiatili's numbers are in finnish timezone instead.
-            let naive_date = NaiveDateTime::from_timestamp(date_int / 1000, 0);
+            let naive_date = NaiveDateTime::from_timestamp_opt(date_int / 1000, 0).expect("parse NaiveDateTime");
             let localtime = Helsinki.from_local_datetime(&naive_date).unwrap();
             let timestamp: DateTime<Utc> = localtime.with_timezone(&Utc);