diff --git a/src/lib.rs b/src/lib.rs
index 0daab92..b5718fb 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -169,7 +169,7 @@ impl std::ops::Sub for Instant {
 impl std::ops::Sub<Duration> for Instant {
     type Output = Instant;
     fn sub(self, rhs: Duration) -> Self::Output {
-        self.checked_add(rhs)
+        self.checked_sub(rhs)
             .expect("overflow when substracting duration from instant")
     }
 }