diff --git a/build/data/obs-studio/locale.ini b/build/data/obs-studio/locale.ini
index 030de64770f8f0dfe32d7b453888158cad7a9610..b5a51cd74cedc6a691bb1afffdc3b7872fe71281 100644
--- a/build/data/obs-studio/locale.ini
+++ b/build/data/obs-studio/locale.ini
@@ -1,18 +1,18 @@
-[en]
+[en-US]
 Name=English
 
-[ru]
+[ru-RU]
 Name=Русский
 
-[fi]
+[fi-FI]
 Name=Finnish
 
-[it]
+[it-IT]
 Name=Italian
 
-[ja]
+[ja-JP]
 Name=日本語
 
-[de]
+[de-DE]
 Name=Deutsch
 
diff --git a/build/data/obs-studio/locale/de.ini b/build/data/obs-studio/locale/de-DE.ini
similarity index 100%
rename from build/data/obs-studio/locale/de.ini
rename to build/data/obs-studio/locale/de-DE.ini
diff --git a/build/data/obs-studio/locale/en.ini b/build/data/obs-studio/locale/en-US.ini
similarity index 100%
rename from build/data/obs-studio/locale/en.ini
rename to build/data/obs-studio/locale/en-US.ini
diff --git a/build/data/obs-studio/locale/fi.ini b/build/data/obs-studio/locale/fi-FI.ini
similarity index 100%
rename from build/data/obs-studio/locale/fi.ini
rename to build/data/obs-studio/locale/fi-FI.ini
diff --git a/build/data/obs-studio/locale/it.ini b/build/data/obs-studio/locale/it-IT.ini
similarity index 100%
rename from build/data/obs-studio/locale/it.ini
rename to build/data/obs-studio/locale/it-IT.ini
diff --git a/build/data/obs-studio/locale/ja.ini b/build/data/obs-studio/locale/ja-JP.ini
similarity index 100%
rename from build/data/obs-studio/locale/ja.ini
rename to build/data/obs-studio/locale/ja-JP.ini
diff --git a/build/data/obs-studio/locale/nb-no.ini b/build/data/obs-studio/locale/nb-NO.ini
similarity index 100%
rename from build/data/obs-studio/locale/nb-no.ini
rename to build/data/obs-studio/locale/nb-NO.ini
diff --git a/build/data/obs-studio/locale/pt.ini b/build/data/obs-studio/locale/pt-PT.ini
similarity index 100%
rename from build/data/obs-studio/locale/pt.ini
rename to build/data/obs-studio/locale/pt-PT.ini
diff --git a/build/data/obs-studio/locale/ru.ini b/build/data/obs-studio/locale/ru-RU.ini
similarity index 100%
rename from build/data/obs-studio/locale/ru.ini
rename to build/data/obs-studio/locale/ru-RU.ini
diff --git a/obs/obs-app.cpp b/obs/obs-app.cpp
index 03be763ec1e35595bda6b403bb34d88bfd02a5ae..d8b1ff810491ef19bf9c3c20a38f9d67a7535407 100644
--- a/obs/obs-app.cpp
+++ b/obs/obs-app.cpp
@@ -97,7 +97,7 @@ static void do_log(int log_level, const char *msg, va_list args, void *param)
 
 bool OBSApp::InitGlobalConfigDefaults()
 {
-	config_set_default_string(globalConfig, "General", "Language", "en");
+	config_set_default_string(globalConfig, "General", "Language", "en-US");
 	config_set_default_uint(globalConfig, "General", "MaxLogs", 10);
 
 #if _WIN32
@@ -156,7 +156,7 @@ bool OBSApp::InitGlobalConfig()
 	return InitGlobalConfigDefaults();
 }
 
-#define DEFAULT_LANG "en"
+#define DEFAULT_LANG "en-US"
 
 bool OBSApp::InitLocale()
 {
diff --git a/test/win/test.cpp b/test/win/test.cpp
index 0e2e2bb7cdf0a8a1d2447d9cdbbd465bad8513cb..cf547fb34604dbcac61729616e1e847b86b568fa 100644
--- a/test/win/test.cpp
+++ b/test/win/test.cpp
@@ -71,7 +71,7 @@ static void CreateOBS(HWND hwnd)
 	RECT rc;
 	GetClientRect(hwnd, &rc);
 
-	if (!obs_startup("en"))
+	if (!obs_startup("en-US"))
 		throw "Couldn't create OBS";
 
 	struct obs_video_info ovi;