diff --git a/examples/shields/rl/13_minigridsb.py b/examples/shields/rl/13_minigridsb.py
index 1cd0a7e..2170a9e 100644
--- a/examples/shields/rl/13_minigridsb.py
+++ b/examples/shields/rl/13_minigridsb.py
@@ -36,7 +36,7 @@ def main():
 
 
     if shield_needed(args.shielding):
-        shield_handler = MiniGridShieldHandler(GRID_TO_PRISM_BINARY, args.grid_file, args.prism_output_file, formula, shield_value=shield_value, shield_comparison=shield_comparison, nocleanup=args.nocleanup, prism_file=None)
+        shield_handler = MiniGridShieldHandler(GRID_TO_PRISM_BINARY, args.grid_file, args.prism_output_file, formula, shield_value=shield_value, shield_comparison=shield_comparison, nocleanup=args.nocleanup, prism_file=args.prism_file)
 
 
     env = gym.make(args.env, render_mode="rgb_array")