diff --git a/viz-core/src/into_response.rs b/viz-core/src/into_response.rs
index 978113f5..0aff2e22 100644
--- a/viz-core/src/into_response.rs
+++ b/viz-core/src/into_response.rs
@@ -111,7 +111,7 @@ where
     fn into_response(self) -> Response {
         self.map_or_else(
             || StatusCode::NOT_FOUND.into_response(),
-            |r| r.into_response(),
+            IntoResponse::into_response,
         )
     }
 }
diff --git a/viz-core/src/middleware/helper.rs b/viz-core/src/middleware/helper.rs
index f0239f36..2099a4c4 100644
--- a/viz-core/src/middleware/helper.rs
+++ b/viz-core/src/middleware/helper.rs
@@ -70,7 +70,7 @@ impl CookieOptions {
 
     /// Creates new `CookieOptions` with `http_only`
     #[must_use]
-    pub fn http_only(mut self, http_only: bool) -> Self {
+    pub const fn http_only(mut self, http_only: bool) -> Self {
         self.http_only = http_only;
         self
     }
diff --git a/viz-core/src/response.rs b/viz-core/src/response.rs
index 6da0398c..5545b050 100644
--- a/viz-core/src/response.rs
+++ b/viz-core/src/response.rs
@@ -226,13 +226,10 @@ impl ResponseExt for Response {
         let value = name
             .map_or_else(
                 || {
-                    if let Some(filename) =
-                        path.as_ref().file_name().and_then(std::ffi::OsStr::to_str)
-                    {
-                        filename
-                    } else {
-                        "download"
-                    }
+                    path.as_ref()
+                        .file_name()
+                        .and_then(std::ffi::OsStr::to_str)
+                        .map_or("download", |filename| filename)
                 },
                 |filename| filename,
             )
diff --git a/viz-core/src/types/cookie.rs b/viz-core/src/types/cookie.rs
index 0d5d3132..4a884493 100644
--- a/viz-core/src/types/cookie.rs
+++ b/viz-core/src/types/cookie.rs
@@ -226,7 +226,7 @@ pub enum CookiesError {
 
 impl From<CookiesError> for Error {
     fn from(e: CookiesError) -> Self {
-        Error::Responder(e.into_response())
+        Self::Responder(e.into_response())
     }
 }
 
diff --git a/viz-core/src/types/header.rs b/viz-core/src/types/header.rs
index bcbd63b1..9df63ba9 100644
--- a/viz-core/src/types/header.rs
+++ b/viz-core/src/types/header.rs
@@ -16,7 +16,7 @@ pub struct Header<T: ?Sized>(pub T);
 impl<T> Header<T> {
     /// Create new `Header` instance.
     #[inline]
-    pub fn new(t: T) -> Self {
+    pub const fn new(t: T) -> Self {
         Self(t)
     }
 
diff --git a/viz-core/src/types/session.rs b/viz-core/src/types/session.rs
index fbef5a31..f33dd7a1 100644
--- a/viz-core/src/types/session.rs
+++ b/viz-core/src/types/session.rs
@@ -54,17 +54,15 @@ impl Session {
     where
         T: DeserializeOwned,
     {
-        let read = self
-            .lock_data()
+        self.lock_data()
             .read()
-            .map_err(|e| responder_error((StatusCode::INTERNAL_SERVER_ERROR, e.to_string())))?;
-
-        let val = read.get(key).cloned();
-
-        match val {
-            Some(t) => from_value(t).map(Some).map_err(report_error),
-            None => Ok(None),
-        }
+            .map_err(|e| responder_error((StatusCode::INTERNAL_SERVER_ERROR, e.to_string())))?
+            .get(key)
+            .cloned()
+            .map_or_else(
+                || Ok(None),
+                |t| from_value(t).map(Some).map_err(report_error),
+            )
     }
 
     /// Sets a value by the key