diff --git a/modules/util/detect.js b/modules/util/detect.js
index a4cf24d7d..1a3928c33 100644
--- a/modules/util/detect.js
+++ b/modules/util/detect.js
@@ -59,14 +59,34 @@ export function utilDetect(force) {
     // Added due to incomplete svg style support. See #715
     detected.opera = (detected.browser.toLowerCase() === 'opera' && parseFloat(detected.version) < 15 );
 
-    detected.locale = (navigator.languages && navigator.languages.length)
-        ? navigator.languages[0] : (navigator.language || navigator.userLanguage || 'en-US');
+    detected.locale = (navigator.language || navigator.userLanguage || 'en-US');
+    detected.language = detected.locale.split('-')[0];
+
+    // Search `navigator.languages` for a better locale.. Prefer the first language,
+    // unless the second language is a culture-specific version of the first one, see #3842
+    if (navigator.languages && navigator.languages.length > 0) {
+        var code0 = navigator.languages[0],
+            parts0 = code0.split('-');
+
+        detected.locale = code0;
+        detected.language = parts0[0];
+
+        if (navigator.languages.length > 1 && parts0.length === 1) {
+            var code1 = navigator.languages[1],
+                parts1 = code1.split('-');
+
+            if (parts1[0] === parts0[0]) {
+                detected.locale = code1;
+            }
+        }
+    }
 
     // Loaded locale is stored in currentLocale
     // return that instead (except in the situation where 'en' might override 'en-US')
     var loadedLocale = currentLocale || 'en';
     if (loadedLocale !== 'en') {
         detected.locale = loadedLocale;
+        detected.language = detected.locale.split('-')[0];
     }
 
     // detect text direction