diff --git a/subgen.py b/subgen.py
index e75412d..6db8e67 100644
--- a/subgen.py
+++ b/subgen.py
@@ -104,7 +104,11 @@ def update_env_variables():
     custom_regroup = os.getenv('CUSTOM_REGROUP', 'cm_sl=84_sl=42++++++1')
     detect_language_length = os.getenv('DETECT_LANGUAGE_LENGTH', 30)
     skipifexternalsub = convert_to_bool(os.getenv('SKIPIFEXTERNALSUB', False))
-    kwargs = ast.literal_eval(os.getenv('SUBGEN_KWARGS', '{}') or '{}')
+    try:
+        kwargs = ast.literal_eval(os.getenv('SUBGEN_KWARGS', '{}') or '{}')
+    except ValueError:
+        kwargs = {}
+        logging.info("kwargs (SUBGEN_KWARGS) is an invalid dictionary, defaulting to empty '{}'")
 
     set_env_variables('subgen.env')