diff --git a/src/approx_const.rs b/src/approx_const.rs
index 3c39b79885c..cfd646765c9 100644
--- a/src/approx_const.rs
+++ b/src/approx_const.rs
@@ -1,12 +1,8 @@
-use rustc::plugin::Registry;
 use rustc::lint::*;
-use rustc::middle::const_eval::lookup_const_by_id;
-use rustc::middle::def::*;
 use syntax::ast::*;
-use syntax::ast_util::{is_comparison_binop, binop_to_string};
-use syntax::ptr::P;
 use syntax::codemap::Span;
 use std::f64::consts as f64;
+
 use utils::span_lint;
 
 declare_lint! {
diff --git a/src/attrs.rs b/src/attrs.rs
index 850155b28b6..3e451ac5eda 100644
--- a/src/attrs.rs
+++ b/src/attrs.rs
@@ -1,11 +1,9 @@
-/// checks for attributes
+//! checks for attributes
 
-use rustc::plugin::Registry;
 use rustc::lint::*;
 use syntax::ast::*;
-use syntax::ptr::P;
-use syntax::codemap::{Span, ExpnInfo};
-use syntax::parse::token::InternedString;
+use syntax::codemap::ExpnInfo;
+
 use utils::{in_macro, match_path, span_lint};
 
 declare_lint! { pub INLINE_ALWAYS, Warn,
diff --git a/src/bit_mask.rs b/src/bit_mask.rs
index 169975001b9..ec937dbab6c 100644
--- a/src/bit_mask.rs
+++ b/src/bit_mask.rs
@@ -1,11 +1,10 @@
-use rustc::plugin::Registry;
 use rustc::lint::*;
 use rustc::middle::const_eval::lookup_const_by_id;
 use rustc::middle::def::*;
 use syntax::ast::*;
-use syntax::ast_util::{is_comparison_binop, binop_to_string};
-use syntax::ptr::P;
+use syntax::ast_util::is_comparison_binop;
 use syntax::codemap::Span;
+
 use utils::span_lint;
 
 declare_lint! {
diff --git a/src/collapsible_if.rs b/src/collapsible_if.rs
index 8a41f208938..0b6dfc19e6b 100644
--- a/src/collapsible_if.rs
+++ b/src/collapsible_if.rs
@@ -12,12 +12,10 @@
 //!
 //! This lint is **warn** by default
 
-use rustc::plugin::Registry;
 use rustc::lint::*;
-use rustc::middle::def::*;
 use syntax::ast::*;
-use syntax::ptr::P;
-use syntax::codemap::{Span, Spanned, ExpnInfo};
+use syntax::codemap::{Spanned, ExpnInfo};
+
 use utils::{in_macro, span_help_and_lint, snippet, snippet_block};
 
 declare_lint! {
diff --git a/src/eq_op.rs b/src/eq_op.rs
index 495696b810c..50b61e23356 100644
--- a/src/eq_op.rs
+++ b/src/eq_op.rs
@@ -3,6 +3,7 @@ use syntax::ast::*;
 use syntax::ast_util as ast_util;
 use syntax::ptr::P;
 use syntax::codemap as code;
+
 use utils::span_lint;
 
 declare_lint! {
diff --git a/src/eta_reduction.rs b/src/eta_reduction.rs
index e0d4182081f..6712e787278 100644
--- a/src/eta_reduction.rs
+++ b/src/eta_reduction.rs
@@ -1,6 +1,5 @@
+use rustc::lint::*;
 use syntax::ast::*;
-use rustc::lint::{Context, LintPass, LintArray, Lint, Level};
-use syntax::codemap::{Span, Spanned};
 use syntax::print::pprust::expr_to_string;
 
 use utils::span_lint;
diff --git a/src/identity_op.rs b/src/identity_op.rs
index 964675b765e..18a475bb737 100644
--- a/src/identity_op.rs
+++ b/src/identity_op.rs
@@ -1,10 +1,7 @@
-use rustc::plugin::Registry;
 use rustc::lint::*;
 use rustc::middle::const_eval::lookup_const_by_id;
 use rustc::middle::def::*;
 use syntax::ast::*;
-use syntax::ast_util::{is_comparison_binop, binop_to_string};
-use syntax::ptr::P;
 use syntax::codemap::Span;
 
 use utils::{span_lint, snippet};
diff --git a/src/len_zero.rs b/src/len_zero.rs
index 94f8d5873ec..073dcea582d 100644
--- a/src/len_zero.rs
+++ b/src/len_zero.rs
@@ -1,14 +1,9 @@
-extern crate rustc_typeck as typeck;
-
-use std::rc::Rc;
-use std::cell::RefCell;
-use syntax::ptr::P;
-use rustc::lint::{Context, LintPass, LintArray, Lint};
-use rustc::util::nodemap::DefIdMap;
-use rustc::middle::ty::{self, TypeVariants, TypeAndMut, MethodTraitItemId, ImplOrTraitItemId};
-use rustc::middle::def::{DefTy, DefStruct, DefTrait};
-use syntax::codemap::{Span, Spanned};
+use rustc::lint::*;
 use syntax::ast::*;
+use syntax::ptr::P;
+use syntax::codemap::{Span, Spanned};
+use rustc::middle::ty::{self, MethodTraitItemId, ImplOrTraitItemId};
+
 use utils::{span_lint, walk_ptrs_ty, snippet};
 
 declare_lint!(pub LEN_ZERO, Warn,
diff --git a/src/lib.rs b/src/lib.rs
index 01a2d65606c..3ce5c1f9f3c 100755
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,7 +1,6 @@
 #![feature(plugin_registrar, box_syntax)]
 #![feature(rustc_private, collections)]
 #![feature(str_split_at)]
-#![allow(unused_imports, unknown_lints)]
 
 #[macro_use]
 extern crate syntax;
diff --git a/src/lifetimes.rs b/src/lifetimes.rs
index 37204f03603..9d07df4a3ed 100644
--- a/src/lifetimes.rs
+++ b/src/lifetimes.rs
@@ -1,10 +1,10 @@
 use syntax::ast::*;
-use rustc::lint::{Context, LintPass, LintArray, Lint};
+use rustc::lint::*;
 use syntax::codemap::Span;
-use syntax::visit::{Visitor, FnKind, walk_ty};
-use utils::{in_external_macro, span_lint};
+use syntax::visit::{Visitor, walk_ty};
 use std::collections::HashSet;
-use std::iter::FromIterator;
+
+use utils::{in_external_macro, span_lint};
 
 declare_lint!(pub NEEDLESS_LIFETIMES, Warn,
               "using explicit lifetimes for references in function arguments when elision rules \
diff --git a/src/methods.rs b/src/methods.rs
index 02b181a46e7..6d0707ccbee 100644
--- a/src/methods.rs
+++ b/src/methods.rs
@@ -1,5 +1,5 @@
 use syntax::ast::*;
-use rustc::lint::{Context, LintPass, LintArray};
+use rustc::lint::*;
 use rustc::middle::ty;
 
 use utils::{span_lint, match_def_path, walk_ptrs_ty};
diff --git a/src/misc.rs b/src/misc.rs
index 091ea36f2f5..1fc41cf4862 100644
--- a/src/misc.rs
+++ b/src/misc.rs
@@ -1,11 +1,11 @@
+use rustc::lint::*;
 use syntax::ptr::P;
 use syntax::ast;
 use syntax::ast::*;
 use syntax::ast_util::{is_comparison_binop, binop_to_string};
-use syntax::visit::{FnKind};
-use rustc::lint::{Context, LintPass, LintArray, Lint, Level};
-use rustc::middle::ty;
 use syntax::codemap::{Span, Spanned};
+use syntax::visit::FnKind;
+use rustc::middle::ty;
 use std::borrow::Cow;
 
 use utils::{match_path, snippet, snippet_block, span_lint, span_help_and_lint, walk_ptrs_ty};
diff --git a/src/mut_mut.rs b/src/mut_mut.rs
index a3c40d06f90..fbcb70e17d3 100644
--- a/src/mut_mut.rs
+++ b/src/mut_mut.rs
@@ -1,8 +1,8 @@
-use syntax::ptr::P;
+use rustc::lint::*;
 use syntax::ast::*;
-use rustc::lint::{Context, LintPass, LintArray, Lint};
-use rustc::middle::ty::{TypeVariants, TypeAndMut, TyRef};
-use syntax::codemap::{BytePos, ExpnInfo, Span};
+use syntax::codemap::ExpnInfo;
+use rustc::middle::ty::{TypeAndMut, TyRef};
+
 use utils::{in_macro, span_lint};
 
 declare_lint!(pub MUT_MUT, Warn,
diff --git a/src/needless_bool.rs b/src/needless_bool.rs
index 2a4ed50b93d..18d98f1f063 100644
--- a/src/needless_bool.rs
+++ b/src/needless_bool.rs
@@ -2,14 +2,9 @@
 //!
 //! This lint is **warn** by default
 
-use rustc::plugin::Registry;
 use rustc::lint::*;
-use rustc::middle::const_eval::lookup_const_by_id;
-use rustc::middle::def::*;
 use syntax::ast::*;
-use syntax::ast_util::{is_comparison_binop, binop_to_string};
-use syntax::ptr::P;
-use syntax::codemap::Span;
+
 use utils::{de_p, span_lint, snippet};
 
 declare_lint! {
diff --git a/src/ptr_arg.rs b/src/ptr_arg.rs
index 85db4aa7b21..2748d187a4e 100644
--- a/src/ptr_arg.rs
+++ b/src/ptr_arg.rs
@@ -2,14 +2,10 @@
 //!
 //! This lint is **warn** by default
 
-use rustc::plugin::Registry;
 use rustc::lint::*;
-use rustc::middle::const_eval::lookup_const_by_id;
-use rustc::middle::def::*;
 use syntax::ast::*;
-use syntax::ast_util::{is_comparison_binop, binop_to_string};
-use syntax::ptr::P;
 use syntax::codemap::Span;
+
 use types::match_ty_unwrap;
 use utils::span_lint;
 
diff --git a/src/returns.rs b/src/returns.rs
index 94b9ec9650f..df0b93f301e 100644
--- a/src/returns.rs
+++ b/src/returns.rs
@@ -1,8 +1,7 @@
-use syntax::ast;
+use rustc::lint::*;
 use syntax::ast::*;
 use syntax::codemap::{Span, Spanned};
 use syntax::visit::FnKind;
-use rustc::lint::{Context, LintPass, LintArray, Level};
 
 use utils::{span_lint, snippet, match_path};
 
@@ -101,7 +100,7 @@ impl LintPass for ReturnPass {
     }
 
     fn check_fn(&mut self, cx: &Context, _: FnKind, _: &FnDecl,
-                block: &Block, _: Span, _: ast::NodeId) {
+                block: &Block, _: Span, _: NodeId) {
         self.check_block_return(cx, block);
         self.check_let_return(cx, block);
     }
diff --git a/src/strings.rs b/src/strings.rs
index 7b7bab49b5d..7981b785850 100644
--- a/src/strings.rs
+++ b/src/strings.rs
@@ -6,9 +6,9 @@
 use rustc::lint::*;
 use rustc::middle::ty::TypeVariants::TyStruct;
 use syntax::ast::*;
-use syntax::codemap::{Span, Spanned};
+use syntax::codemap::Spanned;
+
 use eq_op::is_exp_equal;
-use types::match_ty_unwrap;
 use utils::{match_def_path, span_lint, walk_ptrs_ty, get_parent_expr};
 
 declare_lint! {
diff --git a/src/types.rs b/src/types.rs
index 53d8850c59d..25af398a0b4 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -1,9 +1,9 @@
-use syntax::ptr::P;
+use rustc::lint::*;
 use syntax::ast;
 use syntax::ast::*;
+use syntax::ptr::P;
 use rustc::middle::ty;
-use rustc::lint::{Context, LintPass, LintArray, Lint, Level};
-use syntax::codemap::{ExpnInfo, Span};
+use syntax::codemap::ExpnInfo;
 
 use utils::{in_macro, snippet, span_lint, span_help_and_lint};
 
@@ -40,6 +40,7 @@ pub fn match_ty_unwrap<'a>(ty: &'a Ty, segments: &[&str]) -> Option<&'a [P<Ty>]>
     }
 }
 
+#[allow(unused_imports)]
 impl LintPass for TypePass {
     fn get_lints(&self) -> LintArray {
         lint_array!(BOX_VEC, LINKEDLIST)
diff --git a/src/unicode.rs b/src/unicode.rs
index 62b4a9dadf5..ab48fd1bef2 100644
--- a/src/unicode.rs
+++ b/src/unicode.rs
@@ -1,6 +1,7 @@
 use rustc::lint::*;
 use syntax::ast::*;
 use syntax::codemap::{BytePos, Span};
+
 use utils::span_lint;
 
 declare_lint!{ pub ZERO_WIDTH_SPACE, Deny,
diff --git a/src/utils.rs b/src/utils.rs
index a9378da415a..47e3a3456d6 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -1,11 +1,10 @@
-use rustc::lint::{Context, Lint, Level};
-use syntax::ast::{DefId, Expr, Name, NodeId, Path};
+use rustc::lint::*;
+use syntax::ast::*;
 use syntax::codemap::{ExpnInfo, Span};
 use syntax::ptr::P;
 use rustc::ast_map::Node::NodeExpr;
 use rustc::middle::ty;
-use std::borrow::{Cow, IntoCow};
-use std::convert::From;
+use std::borrow::Cow;
 
 /// returns true if the macro that expanded the crate was outside of
 /// the current crate or was a compiler plugin