diff --git a/compiler/rustc_ast/src/token.rs b/compiler/rustc_ast/src/token.rs
index f583825fbb3..a74464937c8 100644
--- a/compiler/rustc_ast/src/token.rs
+++ b/compiler/rustc_ast/src/token.rs
@@ -434,7 +434,7 @@ impl Token {
             || self == &OpenDelim(Paren)
     }
 
-    /// Returns `true` if the token is any literal
+    /// Returns `true` if the token is any literal.
     pub fn is_lit(&self) -> bool {
         match self.kind {
             Literal(..) => true,