diff --git a/kan/MultKAN.py b/kan/MultKAN.py
index 5ee6b93ea..cc76b5e7e 100644
--- a/kan/MultKAN.py
+++ b/kan/MultKAN.py
@@ -2273,7 +2273,7 @@ def ex_round(ex1, n_digit):
         # define variables
         if var == None:
             for ii in range(1, self.width[0][0] + 1):
-                exec(f"x{ii} = sympy.Symbol('x_{ii}')")
+                exec(f"x{ii} = sympy.Symbol('x_{ii}')", globals())
                 exec(f"x.append(x{ii})")
         elif isinstance(var[0], sympy.Expr):
             x = var