diff --git a/src/async_client.rs b/src/async_client.rs
index f8201011..b4dd6e96 100644
--- a/src/async_client.rs
+++ b/src/async_client.rs
@@ -52,7 +52,6 @@ pub struct AsyncClient {
 #[derive(Default, Debug)]
 pub struct AsyncClientConfig {
     proxy: Option<reqwest::Proxy>,
-    use_sys_proxy: bool,
     user_agent: Option<HeaderValue>,
     disable_ssl_verification: bool,
 }
@@ -63,25 +62,10 @@ impl AsyncClientConfig {
     }
 
     pub fn proxy(mut self, proxy: &str) -> Result<Self, Error> {
-        if self.use_sys_proxy {
-            return Err(Error(InnerError::ConfigurationError(
-                "Using the system proxy has been previously configured.".to_string(),
-            )));
-        }
         self.proxy = Some(reqwest::Proxy::all(proxy)?);
         Ok(self)
     }
 
-    pub fn use_sys_proxy(mut self) -> Result<Self, Error> {
-        if self.proxy.is_some() {
-            return Err(Error(InnerError::ConfigurationError(
-                "A proxy has already been configured.".to_string(),
-            )));
-        }
-        self.use_sys_proxy = true;
-        Ok(self)
-    }
-
     pub fn disable_ssl_verification(mut self) -> Self {
         self.disable_ssl_verification = true;
         self
@@ -162,12 +146,6 @@ impl AsyncClient {
             None => http_client,
         };
 
-        let http_client = if config.use_sys_proxy {
-            http_client.use_sys_proxy()
-        } else {
-            http_client
-        };
-
         let mut headers = reqwest::header::HeaderMap::new();
 
         let user_agent = match config.user_agent {