diff --git a/src/c_macro.rs b/src/c_macro.rs
index a7a7c824e..d5334e9d7 100644
--- a/src/c_macro.rs
+++ b/src/c_macro.rs
@@ -14,11 +14,14 @@ fn is_identifier_starter(c: u8) -> bool {
 }
 
 #[inline(always)]
-fn is_macro(mac: &str, macros: &HashSet<String>) -> bool {
+fn is_macro<S: ::std::hash::BuildHasher>(mac: &str, macros: &HashSet<String, S>) -> bool {
     macros.contains(mac) || PREDEFINED_MACROS.contains(mac)
 }
 
-pub fn replace(code: &[u8], macros: &HashSet<String>) -> Option<Vec<u8>> {
+pub fn replace<S: ::std::hash::BuildHasher>(
+    code: &[u8],
+    macros: &HashSet<String, S>,
+) -> Option<Vec<u8>> {
     let mut new_code = Vec::with_capacity(code.len());
     let mut code_start = 0;
     let mut k_start = 0;
diff --git a/src/lib.rs b/src/lib.rs
index 4e0e439c8..b35cdb9ef 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,5 +1,3 @@
-#![allow(clippy::implicit_hasher)]
-
 #[macro_use]
 extern crate lazy_static;
 #[macro_use]
diff --git a/src/preproc.rs b/src/preproc.rs
index bb84eff83..f99260205 100644
--- a/src/preproc.rs
+++ b/src/preproc.rs
@@ -34,7 +34,10 @@ impl PreprocFile {
     }
 }
 
-pub fn get_macros(file: &PathBuf, files: &HashMap<PathBuf, PreprocFile>) -> HashSet<String> {
+pub fn get_macros<S: ::std::hash::BuildHasher>(
+    file: &PathBuf,
+    files: &HashMap<PathBuf, PreprocFile, S>,
+) -> HashSet<String> {
     let mut macros = HashSet::new();
     if let Some(pf) = files.get(file) {
         for m in pf.macros.iter() {
@@ -51,9 +54,9 @@ pub fn get_macros(file: &PathBuf, files: &HashMap<PathBuf, PreprocFile>) -> Hash
     macros
 }
 
-pub fn fix_includes(
-    files: &mut HashMap<PathBuf, PreprocFile>,
-    all_files: &HashMap<String, Vec<PathBuf>>,
+pub fn fix_includes<S: ::std::hash::BuildHasher>(
+    files: &mut HashMap<PathBuf, PreprocFile, S>,
+    all_files: &HashMap<String, Vec<PathBuf>, S>,
 ) {
     let mut nodes: HashMap<PathBuf, NodeIndex> = HashMap::new();
     // Since we'll remove strong connected components we need to have a stable graph
diff --git a/src/tools.rs b/src/tools.rs
index 85b623d49..33ce0ddef 100644
--- a/src/tools.rs
+++ b/src/tools.rs
@@ -185,10 +185,10 @@ pub fn get_paths_dist(path1: &PathBuf, path2: &PathBuf) -> Option<usize> {
     None
 }
 
-pub fn guess_file(
+pub fn guess_file<S: ::std::hash::BuildHasher>(
     current_path: &PathBuf,
     include_path: &str,
-    all_files: &HashMap<String, Vec<PathBuf>>,
+    all_files: &HashMap<String, Vec<PathBuf>, S>,
 ) -> Vec<PathBuf> {
     //let rpath = include_path.clone();
     let include_path = if include_path.starts_with("mozilla/") {