diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b2699d42d269e858d351add8ee274ee1fe6b464d..866dc01cfb32ab67678619928601f5839935a702 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -65,7 +65,7 @@ rust-nightly-clippy:
       - target/
   <<: *rust_template
   script:
-    - cargo clippy --all --verbose -- -D warnings
+    - cargo clippy --all --tests --verbose -- -D warnings
 
 pages:
   stage: build
diff --git a/src/lib.rs b/src/lib.rs
index fe83c57fb7e7378a32cca2e6ff452ca0bb95c9c6..50b2c9fa26b8a046e7f1e80104870086c1a4884a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,5 @@
+#![deny(rust_2018_idioms, nonstandard_style)]
+#![warn(future_incompatible)]
 #![doc = include_str!("../README.md")]
 
 /// CLI application utilities.
diff --git a/src/rundir.rs b/src/rundir.rs
index 7d1db45c0e397c90ada1834f017b60e91039df8f..35179dafb65c25186131ff88fe9aae64ce0be557 100644
--- a/src/rundir.rs
+++ b/src/rundir.rs
@@ -225,7 +225,7 @@ mod tests {
     use std::path::PathBuf;
 
     #[test]
-    fn test_initialize() -> () {
+    fn test_initialize() {
         // Create dir for the first time.
         let result = RunDir::new("tests/rundir").initialize();
 
@@ -272,21 +272,21 @@ mod tests {
     }
 
     #[test]
-    fn test_subdirs() -> () {
+    fn test_subdirs() {
         let rundir = RunDir::new("tests/rundir2").allow_cleaning(true);
 
         rundir.initialize().unwrap();
 
-        assert_eq!(PathBuf::from("tests/rundir2/subtest").exists(), false);
-        assert_eq!(rundir.subdir_exists("subtest").unwrap(), false);
+        assert!(!PathBuf::from("tests/rundir2/subtest").exists());
+        assert!(!rundir.subdir_exists("subtest").unwrap());
 
         rundir.create_subdir("subtest").unwrap();
-        assert_eq!(PathBuf::from("tests/rundir2/subtest").exists(), true);
-        assert_eq!(rundir.subdir_exists("subtest").unwrap(), true);
+        assert!(PathBuf::from("tests/rundir2/subtest").exists());
+        assert!(rundir.subdir_exists("subtest").unwrap());
 
         rundir.remove_subdir_all("subtest").unwrap();
-        assert_eq!(PathBuf::from("tests/rundir2/subtest").exists(), false);
-        assert_eq!(rundir.subdir_exists("subtest").unwrap(), false);
+        assert!(!PathBuf::from("tests/rundir2/subtest").exists());
+        assert!(!rundir.subdir_exists("subtest").unwrap());
 
         rundir.cleanup().unwrap();
     }
diff --git a/src/str.rs b/src/str.rs
index b5d4be9a1723eac51e73bc7ae944c390adb7a673..d78ce45065f24a30ae893400a8acfb29fcbe412e 100644
--- a/src/str.rs
+++ b/src/str.rs
@@ -14,7 +14,7 @@ mod test {
     use super::*;
 
     #[test]
-    fn test_to_train_case() -> () {
+    fn test_to_train_case() {
         assert_eq!(to_train_case("omg-OMG_omg123 omg"), "OMG_OMG_OMG123_OMG")
     }
 }
diff --git a/src/thread/handle.rs b/src/thread/handle.rs
index ea519903c70e1531be00b2398fafdd71c40619d0..8dac14ce3fe0bb22f2fada8fe92c1507f72576ca 100644
--- a/src/thread/handle.rs
+++ b/src/thread/handle.rs
@@ -154,7 +154,7 @@ mod tests {
 
         let end_handle = handle.get_end_handle();
 
-        assert_eq!((&end_handle).has_ended(), Ok(false));
+        assert_eq!(end_handle.has_ended(), Ok(false));
 
         end_tx.send(()).unwrap();
 
@@ -181,7 +181,7 @@ mod tests {
             end_handles.insert(handle.thread().id(), handle.get_end_handle());
         }
 
-        for (_, end_handle) in &end_handles {
+        for end_handle in end_handles.values() {
             assert_eq!(end_handle.has_ended(), Ok(false));
         }
 
diff --git a/src/thread/monitor.rs b/src/thread/monitor.rs
index b81e01e45ba4553581ed06983cc2380f07264b27..c2cf0d614eb14a031f8786837d12d5039f34e72a 100644
--- a/src/thread/monitor.rs
+++ b/src/thread/monitor.rs
@@ -226,7 +226,7 @@ mod tests {
         let test_handle = thread::spawn(move || {
             let watch_result = MONITOR.watch(Some(&thread_ids)).unwrap();
 
-            assert_eq!(watch_result.is_empty(), false);
+            assert!(!watch_result.is_empty());
             assert_eq!(watch_result[0].id(), handle.thread().id());
         });