diff --git a/src/config.rs b/src/config.rs
index 9e63912..fd2dd51 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -211,7 +211,7 @@ impl Config {
         let re = Regex::new(r"https:\/\/.+\/app-web.*\.js").unwrap();
         let url = re
             .find(&source)
-            .ok_or(Error::not_found("unable to find app-web source"))?;
+            .ok_or_else(|| Error::not_found("unable to find app-web source"))?;
 
         // Get the app-web source.
         let url = url.as_str();
@@ -222,11 +222,11 @@ impl Config {
         let re = Regex::new(r"0x61%2C(0x[0-9a-f]{2}%2C){6}0x67").unwrap();
         let a = re
             .find(&source)
-            .ok_or(Error::not_found("unable to find first half of secret key"))?;
+            .ok_or_else(|| Error::not_found("unable to find first half of secret key"))?;
         let re = Regex::new(r"0x31%2C(0x[0-9a-f]{2}%2C){6}0x34").unwrap();
         let b = re
             .find(&source)
-            .ok_or(Error::not_found("unable to find second half of secret key"))?;
+            .ok_or_else(|| Error::not_found("unable to find second half of secret key"))?;
 
         let a = Self::convert_half(a.as_str())?;
         let b = Self::convert_half(b.as_str())?;
diff --git a/src/decoder.rs b/src/decoder.rs
index 92a0041..facd3e4 100644
--- a/src/decoder.rs
+++ b/src/decoder.rs
@@ -227,7 +227,7 @@ impl Decoder {
             .format;
         let default_track = demuxer
             .default_track()
-            .ok_or(Error::not_found("default track not found"))?;
+            .ok_or_else(|| Error::not_found("default track not found"))?;
 
         let codec_params = &default_track.codec_params;
         let decoder = codecs.make(codec_params, &DecoderOptions::default())?;
diff --git a/src/main.rs b/src/main.rs
index 82b14f6..b24a049 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -354,11 +354,11 @@ async fn run(args: Args) -> Result<ShutdownSignal> {
                 let email = secrets
                     .get("email")
                     .and_then(|email| email.as_str())
-                    .ok_or(Error::unauthenticated("email not found"))?;
+                    .ok_or_else(|| Error::unauthenticated("email not found"))?;
                 let password = secrets
                     .get("password")
                     .and_then(|password| password.as_str())
-                    .ok_or(Error::unauthenticated("password not found"))?;
+                    .ok_or_else(|| Error::unauthenticated("password not found"))?;
 
                 Credentials::Login {
                     email: email.to_string(),
diff --git a/src/player.rs b/src/player.rs
index 249fd95..27b78b8 100644
--- a/src/player.rs
+++ b/src/player.rs
@@ -688,7 +688,7 @@ impl Player {
         let sources = self
             .sources
             .as_mut()
-            .ok_or(Error::unavailable("audio sources not available"))?;
+            .ok_or_else(|| Error::unavailable("audio sources not available"))?;
 
         if track.handle().is_none() {
             let download = tokio::time::timeout(Self::NETWORK_TIMEOUT, async {
@@ -930,7 +930,7 @@ impl Player {
     fn sink_mut(&mut self) -> Result<&mut rodio::Sink> {
         self.sink
             .as_mut()
-            .ok_or(Error::unavailable("audio sink not available"))
+            .ok_or_else(|| Error::unavailable("audio sink not available"))
     }
 
     /// Starts or resumes playback.
@@ -1419,7 +1419,7 @@ impl Player {
                 // This prevents stalling the player when seeking in a track that has not started.
                 match track
                     .handle()
-                    .ok_or(Error::unavailable("download not yet started"))
+                    .ok_or_else(|| Error::unavailable("download not yet started"))
                     .and_then(|_| {
                         self.sink_mut()
                             .and_then(|sink| sink.try_seek(position).map_err(Into::into))
diff --git a/src/proxy.rs b/src/proxy.rs
index dcab4b7..964986b 100644
--- a/src/proxy.rs
+++ b/src/proxy.rs
@@ -66,6 +66,9 @@ pub struct Http {
     url: String,
 }
 
+/// Default HTTPS port.
+const HTTPS_PORT: u16 = 443;
+
 impl Http {
     /// Creates proxy configuration from environment.
     ///
@@ -108,8 +111,8 @@ impl Http {
         let target_url = Url::parse(target)?;
         let host = target_url
             .host_str()
-            .ok_or(Error::invalid_argument("target host not available"))?;
-        let port = target_url.port().unwrap_or(443);
+            .ok_or_else(|| Error::invalid_argument("target host not available"))?;
+        let port = target_url.port().unwrap_or(HTTPS_PORT);
         let tcp_stream = TcpStream::connect(&self.url).await?;
         Self::tunnel(tcp_stream, host, port, self.auth.as_ref()).await
     }
diff --git a/src/remote.rs b/src/remote.rs
index 23f9b64..2ed0bab 100644
--- a/src/remote.rs
+++ b/src/remote.rs
@@ -1970,7 +1970,7 @@ impl Client {
                 let queue = self
                     .queue
                     .as_ref()
-                    .ok_or(Error::internal("no active queue"))?;
+                    .ok_or_else(|| Error::internal("no active queue"))?;
 
                 let player_position = self.player.position();
                 let mut position = player_position;