diff --git a/cranelift/src/filetest/domtree.rs b/cranelift/src/filetest/domtree.rs
index 622b01a891..1063429b17 100644
--- a/cranelift/src/filetest/domtree.rs
+++ b/cranelift/src/filetest/domtree.rs
@@ -1,4 +1,3 @@
-
 //! Test command for verifying dominator trees.
 //!
 //! The `test domtree` test command looks for annotations on instructions like this:
diff --git a/lib/cretonne/src/ir/immediates.rs b/lib/cretonne/src/ir/immediates.rs
index 4af9452bcf..fb55c97006 100644
--- a/lib/cretonne/src/ir/immediates.rs
+++ b/lib/cretonne/src/ir/immediates.rs
@@ -1,4 +1,3 @@
-
 //! Immediate operands for Cretonne instructions
 //!
 //! This module defines the types of immediate operands that can appear on Cretonne instructions.
diff --git a/lib/cretonne/src/ir/types.rs b/lib/cretonne/src/ir/types.rs
index da502f9bf7..8b93e82267 100644
--- a/lib/cretonne/src/ir/types.rs
+++ b/lib/cretonne/src/ir/types.rs
@@ -3,12 +3,6 @@
 use std::default::Default;
 use std::fmt::{self, Display, Debug, Formatter};
 
-// ====--------------------------------------------------------------------------------------====//
-//
-// Value types
-//
-// ====--------------------------------------------------------------------------------------====//
-
 /// The type of an SSA value.
 ///
 /// The `VOID` type is only used for instructions that produce no value. It can't be part of a SIMD
diff --git a/lib/reader/src/lexer.rs b/lib/reader/src/lexer.rs
index 090b85baad..1c422a8027 100644
--- a/lib/reader/src/lexer.rs
+++ b/lib/reader/src/lexer.rs
@@ -1,9 +1,4 @@
-
-// ====--------------------------------------------------------------------------------------====//
-//
-// Lexical analysis for .cton files.
-//
-// ====--------------------------------------------------------------------------------------====//
+//! Lexical analysis for .cton files.
 
 use std::str::CharIndices;
 use std::u16;
diff --git a/lib/reader/src/parser.rs b/lib/reader/src/parser.rs
index 0a63f19029..55cf342ad3 100644
--- a/lib/reader/src/parser.rs
+++ b/lib/reader/src/parser.rs
@@ -1,9 +1,4 @@
-
-// ====--------------------------------------------------------------------------------------====//
-//
-// Parser for .cton files.
-//
-// ====--------------------------------------------------------------------------------------====//
+//! Parser for .cton files.
 
 use std::collections::HashMap;
 use std::str::FromStr;
diff --git a/lib/wasm/src/environ/dummy.rs b/lib/wasm/src/environ/dummy.rs
index 64fb19e262..64733684be 100644
--- a/lib/wasm/src/environ/dummy.rs
+++ b/lib/wasm/src/environ/dummy.rs
@@ -1,3 +1,5 @@
+//! "Dummy" environment for testing wasm translation.
+
 use environ::{FuncEnvironment, GlobalValue, ModuleEnvironment};
 use translation_utils::{Global, Memory, Table, GlobalIndex, TableIndex, SignatureIndex,
                         FunctionIndex, MemoryIndex};
diff --git a/lib/wasm/src/environ/mod.rs b/lib/wasm/src/environ/mod.rs
index a31308b135..f45dbd3161 100644
--- a/lib/wasm/src/environ/mod.rs
+++ b/lib/wasm/src/environ/mod.rs
@@ -1,3 +1,5 @@
+//! Support for configurable wasm translation.
+
 mod spec;
 mod dummy;
 
diff --git a/lib/wasm/src/translation_utils.rs b/lib/wasm/src/translation_utils.rs
index 1f99287b32..8b1bc5fac2 100644
--- a/lib/wasm/src/translation_utils.rs
+++ b/lib/wasm/src/translation_utils.rs
@@ -1,4 +1,4 @@
-///! Helper functions and structures for the translation.
+//! Helper functions and structures for the translation.
 use wasmparser;
 use cretonne;
 use std::u32;