diff --git a/src/duration.rs b/src/duration.rs
index 7c371b1740..c7d6ee9b9a 100644
--- a/src/duration.rs
+++ b/src/duration.rs
@@ -80,10 +80,10 @@ impl Duration {
     /// # Errors
     ///
     /// Returns `None` when the duration is out of bounds, or if `nanos` ≥ 1,000,000,000.
-    pub(crate) const fn new(secs: i64, nanos: u32) -> Option<Duration> {
+    pub const fn new(secs: i64, nanos: u32) -> Option<Duration> {
         if secs < MIN.secs
             || secs > MAX.secs
-            || nanos > 1_000_000_000
+            || nanos >= 1_000_000_000
             || (secs == MAX.secs && nanos > MAX.nanos as u32)
             || (secs == MIN.secs && nanos < MIN.nanos as u32)
         {