diff --git a/src/config.rs b/src/config.rs
index d0fedef..6a88f0d 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -12,7 +12,7 @@ pub struct RiotApiConfig {
     pub(crate) retries: u8,
     pub(crate) burst_pct: f32,
     pub(crate) duration_overhead: Duration,
-    pub(crate) reqwest_client: ClientBuilder,
+    pub(crate) client_builder: Option<ClientBuilder>,
 }
 
 impl RiotApiConfig {
@@ -42,7 +42,7 @@ impl RiotApiConfig {
             retries: 3,
             burst_pct: Self::PRECONFIG_BURST_BURST_PCT,
             duration_overhead: Duration::from_millis(Self::PRECONFIG_BURST_DURATION_OVERHEAD_MILLIS),
-            reqwest_client: ClientBuilder::new(),
+            client_builder: Some(ClientBuilder::new()),
         }
     }
 
@@ -147,4 +147,13 @@ impl RiotApiConfig {
         self.duration_overhead = duration_overhead;
         self
     }
+
+    /// Sets the reqwest `ClientBuilder`.
+    ///
+    /// # Returns
+    /// `self`, for chaining.
+    pub fn set_client_builder(mut self, client_builder: ClientBuilder) -> Self {
+        self.client_builder = Some(client_builder);
+        self
+    }
 }
diff --git a/src/riot_api.rs b/src/riot_api.rs
index 90641d4..34733ab 100644
--- a/src/riot_api.rs
+++ b/src/riot_api.rs
@@ -31,11 +31,12 @@ pub struct RiotApi {
 }
 
 impl RiotApi {
-    pub fn with_config(config: RiotApiConfig) -> Self {
-        log::trace!("Creating client (TODO: configuration).");
+    pub fn with_config(mut config: RiotApiConfig) -> Self {
+        let client_builder = config.client_builder.take()
+            .expect("!NONE CLIENT_BUILDER IN CONFIG.");
         Self {
             config: config,
-            client: Client::new(),
+            client: client_builder.build().expect("Failed to create client from builder."),
             regional_requesters: InsertOnlyCHashMap::new(),
         }
     }
diff --git a/tests/tests_na.rs b/tests/tests_na.rs
index 3094c51..df88255 100644
--- a/tests/tests_na.rs
+++ b/tests/tests_na.rs
@@ -59,7 +59,6 @@ async_tests!{
         // match_get_old: async {
         //     let p = RIOT_API.match_v4().get_match(Region::NA, 2632789562);
         //     let m = p.await.map_err(|e| e.to_string())?.ok_or("Failed to get match.".to_owned())?;
-        //     // TODO.
         //     Ok(())
         // },
         match_get_aram: async {