diff --git a/crates/ui-egui/src/i18n/tests.rs b/crates/ui-egui/src/i18n/tests.rs
index e3464cf98a..f30edd8c86 100644
--- a/crates/ui-egui/src/i18n/tests.rs
+++ b/crates/ui-egui/src/i18n/tests.rs
@@ -39,6 +39,18 @@ fn translations(code: &str) -> String {
     lang.catalog_texts().flat_map(rows).flat_map(|(_, _, t)| t.split('|').map(str::to_owned).collect::<Vec<_>>()).collect()
 }
 
+#[test]
+fn the_macos_bundle_declares_every_interface_language() {
+    // AppKit translates its own dialogs (open and save panels) only into the languages the app
+    // bundle declares, so `CFBundleLocalizations` must list every entry of `LANGUAGES`.
+    let plist = include_str!("../../../../packaging/macos/Info.plist.in");
+    let block = plist.split("<key>CFBundleLocalizations</key>").nth(1).expect("the template declares CFBundleLocalizations");
+    let block = block.split("</array>").next().expect("the declaration is an array");
+    let declared: Vec<String> = block.split("<string>").skip(1).filter_map(|s| s.split("</string>").next()).map(str::to_lowercase).collect();
+    let registered: Vec<String> = LANGUAGES.iter().map(|l| l.code.to_lowercase()).collect();
+    assert_eq!(declared, registered, "packaging/macos/Info.plist.in and LANGUAGES list different languages");
+}
+
 #[test]
 fn keyboard_key_names_have_a_separate_context_and_english_fallback() {
     let keys = fixture_lang("x-keys", "key\tDelete\tEntf\n\tDelete\tLöschen\n\tOpen\tÖffnen\n");
diff --git a/packaging/macos/Info.plist.in b/packaging/macos/Info.plist.in
index cfc7d2d08e..f38f186c82 100644
--- a/packaging/macos/Info.plist.in
+++ b/packaging/macos/Info.plist.in
@@ -6,6 +6,46 @@
 <dict>
   <key>CFBundleDevelopmentRegion</key>
   <string>en</string>
+  <!-- UI translations are embedded in Rust; declare them for AppKit's system dialogs (open and
+       save panels, overwrite confirmation). Keep in sync with LANGUAGES in crates/ui-egui/src/i18n.rs. -->
+  <key>CFBundleLocalizations</key>
+  <array>
+    <string>en</string>
+    <string>ja</string>
+    <string>zh-Hans</string>
+    <string>zh-Hant</string>
+    <string>cs</string>
+    <string>pt-BR</string>
+    <string>de</string>
+    <string>es</string>
+    <string>fr</string>
+    <string>ru</string>
+    <string>kk</string>
+    <string>bg</string>
+    <string>te</string>
+    <string>hu</string>
+    <string>uk</string>
+    <string>it</string>
+    <string>ar</string>
+    <string>ckb</string>
+    <string>fa</string>
+    <string>pl</string>
+    <string>sl</string>
+    <string>el</string>
+    <string>tr</string>
+    <string>lt</string>
+    <string>id</string>
+    <string>vi</string>
+    <string>fi</string>
+    <string>sq</string>
+    <string>th</string>
+    <string>ca</string>
+    <string>ro</string>
+    <string>lo</string>
+    <string>hi</string>
+    <string>ko</string>
+    <string>nb</string>
+  </array>
   <key>CFBundleDisplayName</key>
   <string>PdfCraft</string>
   <key>CFBundleName</key>