diff --git a/highcharts_core/js_literal_functions.py b/highcharts_core/js_literal_functions.py
index 31be9df..e6ea0fa 100644
--- a/highcharts_core/js_literal_functions.py
+++ b/highcharts_core/js_literal_functions.py
@@ -400,6 +400,8 @@ def get_js_literal(item, careful_validation = False) -> str:
         as_str += """null"""
     elif HAS_NUMPY and not isinstance(item, (dict, UserDict, Decimal)) and np.isnan(item):
         as_str += """null"""
+    elif HAS_NUMPY and not isinstance(item, (dict, UserDict)) and np.isnan(item):
+        as_str += """null"""
     elif item is True:
         as_str += """true"""
     elif item is False: