diff --git a/src/sage/numerical/interactive_simplex_method.py b/src/sage/numerical/interactive_simplex_method.py
index 2beaae0fe2c..4b227304ad8 100644
--- a/src/sage/numerical/interactive_simplex_method.py
+++ b/src/sage/numerical/interactive_simplex_method.py
@@ -3913,6 +3913,22 @@ def __init__(self, A, b, c, objective_value,
         self._AbcvBNz = [A, b, c, objective_value, B, N, SR(objective_name)]
 
     def __copy__(self):
+        r"""
+        TESTS::
+            sage: A = ([1, 1], [3, 1])
+            sage: b = (1000, 1500)
+            sage: c = (10, 5)
+            sage: P = InteractiveLPProblemStandardForm(A, b, c)
+            sage: D = P.initial_dictionary()
+            sage: D_2 = copy(D)
+            sage: D is D_2
+            False
+            sage: D.enter('x1')
+            sage: D.leave('x3')
+            sage: D.update()
+            sage: D_2 == D
+            False
+        """
         return type(self)(*self._AbcvBNz)
 
     @staticmethod