diff --git a/tests/basics/set_binop.py b/tests/basics/set_binop.py
index a3657d84bdca86317b0024361a554011e09dc9c5..7848920b6a9742086968f22001f29859cf6d4ce7 100644
--- a/tests/basics/set_binop.py
+++ b/tests/basics/set_binop.py
@@ -29,6 +29,25 @@ for s in sets:
 
 print(set('abc') == 1)
 
+# make sure inplace operators modify the set
+
+s1 = s2 = set('abc')
+s1 |= set('ad')
+print(s1 is s2, len(s1))
+
+s1 = s2 = set('abc')
+s1 ^= set('ad')
+print(s1 is s2, len(s1))
+
+s1 = s2 = set('abc')
+s1 &= set('ad')
+print(s1 is s2, len(s1))
+
+s1 = s2 = set('abc')
+s1 -= set('ad')
+print(s1 is s2, len(s1))
+
+# unsupported operator
 try:
     set('abc') * 2
 except TypeError: