diff --git a/crates/ra_parser/src/grammar.rs b/crates/ra_parser/src/grammar.rs
index 22f64a9f4add..a46e11e1d945 100644
--- a/crates/ra_parser/src/grammar.rs
+++ b/crates/ra_parser/src/grammar.rs
@@ -1,7 +1,7 @@
 //! This is the actual "grammar" of the Rust language.
 //!
 //! Each function in this module and its children corresponds
-//! to a production of the format grammar. Submodules roughly
+//! to a production of the formal grammar. Submodules roughly
 //! correspond to different *areas* of the grammar. By convention,
 //! each submodule starts with `use super::*` import and exports
 //! "public" productions via `pub(super)`.
diff --git a/xtask/src/codegen/gen_syntax.rs b/xtask/src/codegen/gen_syntax.rs
index 19fea67d8bfb..db05dcebb01c 100644
--- a/xtask/src/codegen/gen_syntax.rs
+++ b/xtask/src/codegen/gen_syntax.rs
@@ -1,4 +1,4 @@
-//! This module generate AST datatype used by rust-analyzer.
+//! This module generates AST datatype used by rust-analyzer.
 //!
 //! Specifically, it generates the `SyntaxKind` enum and a number of newtype
 //! wrappers around `SyntaxNode` which implement `ra_syntax::AstNode`.
diff --git a/xtask/src/lib.rs b/xtask/src/lib.rs
index 0a569cf5dc6f..9b0afe8e0cf7 100644
--- a/xtask/src/lib.rs
+++ b/xtask/src/lib.rs
@@ -53,6 +53,7 @@ fn reformat(text: impl std::fmt::Display) -> Result<String> {
     write!(rustfmt.stdin.take().unwrap(), "{}", text)?;
     let output = rustfmt.wait_with_output()?;
     let stdout = String::from_utf8(output.stdout)?;
+    // TODO: update the preable: replace ra_tools with the relevant path
     let preamble = "Generated file, do not edit by hand, see `crate/ra_tools/src/codegen`";
     Ok(format!("//! {}\n\n{}", preamble, stdout))
 }