diff --git a/crates/cli/src/commands/config.rs b/crates/cli/src/commands/config.rs
index a1b57d3e..1bfdbb11 100644
--- a/crates/cli/src/commands/config.rs
+++ b/crates/cli/src/commands/config.rs
@@ -310,8 +310,10 @@ async fn sync(root: &super::Options, prune: bool, dry_run: bool) -> anyhow::Resu
                         jwks_uri_override: provider.jwks_uri,
                         discovery_mode,
                         pkce_mode,
-                        // TODO: get that from the config
-                        additional_authorization_parameters: Vec::new(),
+                        additional_authorization_parameters: provider
+                            .additional_authorization_parameters
+                            .into_iter()
+                            .collect(),
                     },
                 )
                 .await?;
diff --git a/crates/config/src/sections/upstream_oauth2.rs b/crates/config/src/sections/upstream_oauth2.rs
index 913c3f2c..e26362f6 100644
--- a/crates/config/src/sections/upstream_oauth2.rs
+++ b/crates/config/src/sections/upstream_oauth2.rs
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::ops::Deref;
+use std::{ops::Deref, collections::BTreeMap};
 
 use async_trait::async_trait;
 use mas_iana::{jose::JsonWebSignatureAlg, oauth::OAuthClientAuthenticationMethod};
@@ -302,6 +302,12 @@ pub struct Provider {
     /// provider
     #[serde(default)]
     pub claims_imports: ClaimsImports,
+
+    /// Additional parameters to include in the authorization request
+    ///
+    /// Orders of the keys are not preserved.
+    #[serde(default)]
+    pub additional_authorization_parameters: BTreeMap<String, String>,
 }
 
 impl Deref for Provider {
diff --git a/docs/config.schema.json b/docs/config.schema.json
index 6bd9e013..eb358ccf 100644
--- a/docs/config.schema.json
+++ b/docs/config.schema.json
@@ -2084,6 +2084,14 @@
               "$ref": "#/definitions/ClaimsImports"
             }
           ]
+        },
+        "additional_authorization_parameters": {
+          "description": "Additional parameters to include in the authorization request\n\nOrders of the keys are not preserved.",
+          "default": {},
+          "type": "object",
+          "additionalProperties": {
+            "type": "string"
+          }
         }
       }
     },