diff --git a/scripts/languages/twlang.py b/scripts/languages/twlang.py
index c682cd282..6508a79c1 100644
--- a/scripts/languages/twlang.py
+++ b/scripts/languages/twlang.py
@@ -59,12 +59,16 @@ def decode(fileobj, elements_per_key):
 				data[current_key].append(index)
 			if line in data:
 				raise LanguageDecodeError("Key defined multiple times: " + line, fileobj.name, index)
-			data[(line, current_context)] = [index]
+			data[(line, current_context)] = [index - 1 if current_context else index]
 			current_key = (line, current_context)
 	if len(data[current_key]) != 1+elements_per_key:
 		raise LanguageDecodeError("Wrong number of elements per key", fileobj.name, index)
 	data[current_key].append(index+1)
-	return data
+	new_data = {}
+	for key, value in data.items():
+		if key[0]:
+			new_data[key] = value
+	return new_data
 
 
 def check_file(path):
@@ -78,7 +82,7 @@ def check_folder(path):
 	for path2, dirs, files in os.walk(path):
 		dirs.sort()
 		for f in sorted(files):
-			if not any(f.endswith(x) for x in ".cpp .c .h".split()):
+			if not any(f.endswith(x) for x in [".cpp", ".c", ".h"]):
 				continue
 			for sentence in check_file(os.path.join(path2, f)):
 				englishlist[sentence[1:]] = None