diff --git a/mapytex/calculus/core/random/__init__.py b/mapytex/calculus/core/random/__init__.py
index 70bbe24..76f9709 100644
--- a/mapytex/calculus/core/random/__init__.py
+++ b/mapytex/calculus/core/random/__init__.py
@@ -228,7 +228,7 @@ def build_variable_scope(rd_variables, rejected, min_max, variables_scope):
     >>> completed == complete
     True
     """
-    complete_scope = variables_scope
+    complete_scope = variables_scope.copy()
     for v in rd_variables:
         try:
             complete_scope[v]