diff --git a/gui/utils.py b/gui/utils.py
index a205259..056be0e 100644
--- a/gui/utils.py
+++ b/gui/utils.py
@@ -6,7 +6,7 @@ from draw.Iinstruction import *
 
 def nassi(filepath:str, output_path: str, gui, font_filepath: str=None):
     NSD = NassiShneidermanDiagram(gui.debug_mode)
-    if font_filepath:
+    if font_filepath is not None and font_filepath is not "":
         NSD.set_font(font_filepath)
     NSD.load_from_file(filepath)
     NSD.convert_to_image(output_path, 500)