diff --git a/rust/hg-core/src/revlog.rs b/rust/hg-core/src/revlog.rs
--- a/rust/hg-core/src/revlog.rs
+++ b/rust/hg-core/src/revlog.rs
@@ -14,7 +14,7 @@
 /// Marker expressing the absence of a parent
 ///
 /// Independently of the actual representation, `NULL_REVISION` is guaranteed
-/// to be smaller that all existing revisions.
+/// to be smaller than all existing revisions.
 pub const NULL_REVISION: Revision = -1;
 
 /// Same as `mercurial.node.wdirrev`