diff --git a/PowerEditor/src/Parameters.cpp b/PowerEditor/src/Parameters.cpp
index 8ace90d62..5d02d2eed 100644
--- a/PowerEditor/src/Parameters.cpp
+++ b/PowerEditor/src/Parameters.cpp
@@ -4262,6 +4262,8 @@ LangType NppParameters::getLangIDFromStr(const TCHAR *langName)
 
 generic_string NppParameters::getLocPathFromStr(const generic_string & localizationCode)
 {
+	if (localizationCode == TEXT("en") || localizationCode == TEXT("en-au") || localizationCode == TEXT("en-bz") || localizationCode == TEXT("en-ca") || localizationCode == TEXT("en-cb") || localizationCode == TEXT("en-gb") || localizationCode == TEXT("en-ie") || localizationCode == TEXT("en-jm") || localizationCode == TEXT("en-nz") || localizationCode == TEXT("en-ph") || localizationCode == TEXT("en-tt") || localizationCode == TEXT("en-us") || localizationCode == TEXT("en-za") || localizationCode == TEXT("en-zw"))
+		return TEXT("english.xml");
 	if (localizationCode == TEXT("af"))
 		return TEXT("afrikaans.xml");
 	if (localizationCode == TEXT("sq"))
diff --git a/PowerEditor/src/winmain.cpp b/PowerEditor/src/winmain.cpp
index 80ac005d9..9ec48c417 100644
--- a/PowerEditor/src/winmain.cpp
+++ b/PowerEditor/src/winmain.cpp
@@ -251,6 +251,7 @@ generic_string getLocalizationPathFromParam(ParamVector & params)
 	generic_string locStr;
 	if (!getParamVal('L', params, locStr))
 		return TEXT("");
+	locStr = stringToLower(stringReplace(locStr, TEXT("_"), TEXT("-"))); // convert to lowercase format with "-" as separator
 	return NppParameters::getLocPathFromStr(locStr.c_str());
 }