diff --git a/ios/engine/KMEI/KeymanEngineTests/AssociatingPackageInstallerTests.swift b/ios/engine/KMEI/KeymanEngineTests/AssociatingPackageInstallerTests.swift
index 3ac03b6077..3ca58e6056 100644
--- a/ios/engine/KMEI/KeymanEngineTests/AssociatingPackageInstallerTests.swift
+++ b/ios/engine/KMEI/KeymanEngineTests/AssociatingPackageInstallerTests.swift
@@ -325,4 +325,35 @@ class AssociatingPackageInstallerTests: XCTestCase {
     XCTAssertNil(Storage.active.userDefaults.userKeyboards)
     XCTAssertNil(Storage.active.userDefaults.userLexicalModels)
   }
+
+  func testPackageLanguageMismatch() throws {
+    guard let strPackage = try ResourceFileManager.shared.prepareKMPInstall(from: TestUtils.Keyboards.fvSencotenKMP) as? KeyboardKeymanPackage else {
+      XCTFail()
+      return
+    }
+
+    guard let eurolatinPackage = try ResourceFileManager.shared.prepareKMPInstall(from: TestUtils.Keyboards.silEuroLatinKMP) as? KeyboardKeymanPackage else {
+      XCTFail()
+      return
+    }
+
+    let strInstaller = AssociatingPackageInstaller(for: strPackage,
+                                                defaultLanguageCode: "str", // correct code:  str-latn
+                                                downloadManager: downloadManager) { _ in
+    }
+
+    // Package does not contain "str", but does contain "str-latn"
+    XCTAssertEqual(strInstaller.defaultLgCode, "str-latn")
+
+    let eurolatinInstaller = AssociatingPackageInstaller(for: eurolatinPackage,
+                                                defaultLanguageCode: "en-fake-bcp", // correct code:  "en"
+                                                downloadManager: downloadManager) { _ in
+    }
+
+    // Package does not contain "en-fake-bcp", but does contain "en".
+    XCTAssertEqual(eurolatinInstaller.defaultLgCode, "en")
+
+    // Note:  the current naive approach isn't exactly BCP-47 subtag aware - it relies on one tag
+    // containing the entire other tag as a substring.
+  }
 }
diff --git a/ios/engine/KMEI/KeymanEngineTests/TestUtils/Keyboards.swift b/ios/engine/KMEI/KeymanEngineTests/TestUtils/Keyboards.swift
index 041cd8b7a1..065b8fd476 100644
--- a/ios/engine/KMEI/KeymanEngineTests/TestUtils/Keyboards.swift
+++ b/ios/engine/KMEI/KeymanEngineTests/TestUtils/Keyboards.swift
@@ -13,6 +13,7 @@ extension TestUtils {
   enum Keyboards {
     static let khmerAngkorKMP = TestUtils.keyboardsBundle.url(forResource: "khmer_angkor", withExtension: "kmp")!
     static let silEuroLatinKMP = TestUtils.keyboardsBundle.url(forResource: "sil_euro_latin", withExtension: "kmp")!
+    static let fvSencotenKMP = TestUtils.keyboardsBundle.url(forResource: "fv_sencoten", withExtension: "kmp")!
     
     static let khmer_angkor =  InstallableKeyboard(id: "khmer_angkor",
                                                    name: "Khmer Angkor",
@@ -43,5 +44,15 @@ extension TestUtils {
                                                    font: Font(family: "LatinWeb", source: ["DejaVuSans.ttf"], size: nil),
                                                    oskFont: nil,
                                                    isCustom: false)
+
+    static let fv_sencoten = InstallableKeyboard(id: "fv_sencoten",
+                                                 name: "SENĆOŦEN",
+                                                 languageID: "str-latn",
+                                                 languageName: "Salish, Straits (Latin)",
+                                                 version: "9.1",
+                                                 isRTL: false,
+                                                 font: nil,
+                                                 oskFont: nil,
+                                                 isCustom: false)
   }
 }