diff --git a/deltachat-jsonrpc/src/api/types/login_param.rs b/deltachat-jsonrpc/src/api/types/login_param.rs
index 72b8fd66b1..36d6ed9ffc 100644
--- a/deltachat-jsonrpc/src/api/types/login_param.rs
+++ b/deltachat-jsonrpc/src/api/types/login_param.rs
@@ -122,6 +122,7 @@ impl TryFrom<EnteredLoginParam> for dc::EnteredLoginParam {
                 password: param.smtp_password.unwrap_or_default(),
             },
             certificate_checks: param.certificate_checks.unwrap_or_default().into(),
+            oauth2: false,
         })
     }
 }
diff --git a/src/login_param.rs b/src/login_param.rs
index 723621b432..1f1c0eb284 100644
--- a/src/login_param.rs
+++ b/src/login_param.rs
@@ -140,6 +140,10 @@ pub struct EnteredLoginParam {
     /// TLS options: whether to allow invalid certificates and/or
     /// invalid hostnames
     pub certificate_checks: EnteredCertificateChecks,
+
+    /// Deprecated 2026-07, always false
+    #[serde(default)]
+    pub oauth2: bool,
 }
 
 impl EnteredLoginParam {
@@ -235,6 +239,7 @@ impl EnteredLoginParam {
                 password: send_pw,
             },
             certificate_checks,
+            oauth2: false,
         })
     }
 
@@ -396,6 +401,7 @@ mod tests {
                 password: "".to_string(),
             },
             certificate_checks: Default::default(),
+            oauth2: false,
         };
         param.save_legacy(&t).await?;
         assert_eq!(
diff --git a/src/qr.rs b/src/qr.rs
index 4059382753..9a07249555 100644
--- a/src/qr.rs
+++ b/src/qr.rs
@@ -841,6 +841,7 @@ pub(crate) async fn login_param_from_account_qr(
             },
             smtp: Default::default(),
             certificate_checks: EnteredCertificateChecks::Strict,
+            oauth2: false,
         };
         return Ok(param);
     }
@@ -860,6 +861,7 @@ pub(crate) async fn login_param_from_account_qr(
             },
             smtp: Default::default(),
             certificate_checks: EnteredCertificateChecks::Strict,
+            oauth2: false,
         };
 
         Ok(param)
diff --git a/src/qr/dclogin_scheme.rs b/src/qr/dclogin_scheme.rs
index 97e06ceb87..5ef2c47ab2 100644
--- a/src/qr/dclogin_scheme.rs
+++ b/src/qr/dclogin_scheme.rs
@@ -196,6 +196,7 @@ pub(crate) fn login_param_from_login_qr(
                     password: smtp_password.unwrap_or_default(),
                 },
                 certificate_checks: certificate_checks.unwrap_or_default(),
+                oauth2: false,
             };
             Ok(param)
         }
diff --git a/src/transport.rs b/src/transport.rs
index 1d4f54b35e..c2ef62260f 100644
--- a/src/transport.rs
+++ b/src/transport.rs
@@ -212,6 +212,10 @@ pub(crate) struct ConfiguredLoginParamJson {
     pub smtp_password: String,
 
     pub certificate_checks: ConfiguredCertificateChecks,
+
+    /// Deprecated 2026-07, always false
+    #[serde(default)]
+    pub oauth2: bool,
 }
 
 impl fmt::Display for ConfiguredLoginParam {
@@ -488,6 +492,7 @@ impl From<ConfiguredLoginParam> for ConfiguredLoginParamJson {
             smtp_password: configured_login_param.smtp_password,
 
             certificate_checks: configured_login_param.certificate_checks,
+            oauth2: false,
         }
     }
 }
diff --git a/src/transport/transport_tests.rs b/src/transport/transport_tests.rs
index f31661ca06..ec44a7bfd0 100644
--- a/src/transport/transport_tests.rs
+++ b/src/transport/transport_tests.rs
@@ -52,7 +52,7 @@ async fn test_save_load_login_param() -> Result<()> {
         .clone()
         .save_to_transports_table(&t, &EnteredLoginParam::default(), time())
         .await?;
-    let expected_param = r#"{"addr":"alice@example.org","imap":[{"connection":{"host":"imap.example.com","port":123,"security":"Starttls"},"user":"alice"}],"imap_folder":"Folder","imap_user":"","imap_password":"foo","smtp":[{"connection":{"host":"smtp.example.com","port":456,"security":"Tls"},"user":"alice@example.org"}],"smtp_user":"","smtp_password":"bar","certificate_checks":"Strict"}"#;
+    let expected_param = r#"{"addr":"alice@example.org","imap":[{"connection":{"host":"imap.example.com","port":123,"security":"Starttls"},"user":"alice"}],"imap_folder":"Folder","imap_user":"","imap_password":"foo","smtp":[{"connection":{"host":"smtp.example.com","port":456,"security":"Tls"},"user":"alice@example.org"}],"smtp_user":"","smtp_password":"bar","certificate_checks":"Strict","oauth2":false}"#;
     assert_eq!(
         t.sql
             .query_get_value::<String>("SELECT configured_param FROM transports", ())