diff --git a/flutter/lib/web/bridge.dart b/flutter/lib/web/bridge.dart
index 087d300c1..6c2c23f57 100644
--- a/flutter/lib/web/bridge.dart
+++ b/flutter/lib/web/bridge.dart
@@ -901,7 +901,11 @@ class RustdeskImpl {
   }
 
   String mainGetLocalOption({required String key, dynamic hint}) {
-    return js.context.callMethod('getByName', ['option:local', key]);
+    final v = js.context.callMethod('getByName', ['option:local', key]);
+    if (key == 'lang' && (v == 'pt' || v == 'br')) {
+      return 'pt-br';
+    }
+    return v;
   }
 
   // Do not return the real environment variables.
diff --git a/src/common.rs b/src/common.rs
index 23aa489a5..c98627187 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -1197,6 +1197,9 @@ pub fn get_local_option(key: &str) -> String {
             }
         }
     }
+    if key == "lang" && (v == "pt" || v == "br") {
+        return "pt-br".to_owned();
+    }
     v
 }
 
diff --git a/src/lang.rs b/src/lang.rs
index 27adcc1a5..8045dcb60 100644
--- a/src/lang.rs
+++ b/src/lang.rs
@@ -34,6 +34,7 @@ mod nb;
 mod nl;
 mod pl;
 mod ptbr;
+mod pt_PT;
 mod ro;
 mod ru;
 mod sc;
@@ -63,7 +64,8 @@ pub const LANGS: &[(&str, &str)] = &[
     ("nb", "Norsk bokmål"),
     ("zh-cn", "简体中文"),
     ("zh-tw", "繁體中文"),
-    ("pt", "Português"),
+    ("pt-pt", "Português (Portugal)"),
+    ("pt-br", "Português (Brasil)"),
     ("es", "Español"),
     ("et", "Eesti keel"),
     ("eu", "Euskara"),
@@ -143,6 +145,21 @@ fn resolve_lang(saved_lang: &str, locale: &str, cjk_fallback: bool) -> String {
             .to_owned();
         }
     }
+    if lang.is_empty() {
+        // pt_PT on Linux, pt-PT on mac, pt_PT on Android.
+        // Per CLDR locale inheritance, every Portuguese-speaking locale
+        // besides bare "pt" and Brazil's own variants (pt-BR/pt_BR) has
+        // pt-PT as its parent (Angola, Mozambique, Cape Verde, etc.),
+        // so it should resolve to European Portuguese.
+        if locale.starts_with("pt") {
+            lang = (if locale == "pt" || locale.starts_with("pt-br") || locale.starts_with("pt_br") {
+                "pt-br"
+            } else {
+                "pt-pt"
+            })
+            .to_owned();
+        }
+    }
     if lang.is_empty() {
         lang = locale
             .split("-")
@@ -187,6 +204,8 @@ pub fn translate_locale(name: String, locale: &str) -> String {
         "id" => id::T.deref(),
         "br" => ptbr::T.deref(),
         "pt" => ptbr::T.deref(),
+        "pt-br" => ptbr::T.deref(),
+        "pt-pt" => pt_PT::T.deref(),
         "tr" => tr::T.deref(),
         "cs" => cs::T.deref(),
         "da" => da::T.deref(),
@@ -344,4 +363,24 @@ mod test {
         assert_eq!(f("", "zh_TW", false), "zh-tw");
         assert_eq!(f("", "ja-JP", false), "ja");
     }
+
+    #[test]
+    fn test_resolve_lang_detects_pt_pt_and_pt_br_from_locale() {
+        use super::resolve_lang as f;
+
+        assert_eq!(f("", "pt-PT", false), "pt-pt");
+        assert_eq!(f("", "pt_PT", false), "pt-pt");
+        assert_eq!(f("", "pt-BR", false), "pt-br");
+        assert_eq!(f("", "pt_BR", false), "pt-br");
+        assert_eq!(f("", "pt-AO", false), "pt-pt");
+        assert_eq!(f("", "pt-MZ", false), "pt-pt");
+    }
+
+    #[test]
+    fn test_resolve_lang_saved_lang_takes_precedence_over_locale() {
+        use super::resolve_lang as f;
+
+        assert_eq!(f("pt-br", "pt-PT", false), "pt-br");
+        assert_eq!(f("pt-pt", "pt-BR", false), "pt-pt");
+    }
 }