diff --git a/tools/testing/selftests/net/lib/py/nsim.py b/tools/testing/selftests/net/lib/py/nsim.py
index 97457aca7e08..94aa32f59fdb 100644
--- a/tools/testing/selftests/net/lib/py/nsim.py
+++ b/tools/testing/selftests/net/lib/py/nsim.py
@@ -84,6 +84,17 @@ class NetdevSimDev:
         for port_index in range(port_count):
             self.nsims.append(self._make_port(port_index, ifnames[port_index]))
 
+        self.removed = False
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, ex_type, ex_value, ex_tb):
+        """
+        __exit__ gets called at the end of a "with" block.
+        """
+        self.remove()
+
     def _make_port(self, port_index, ifname):
         return NetdevSim(self, port_index, ifname, self.ns)
 
@@ -112,7 +123,9 @@ class NetdevSimDev:
             raise Exception("netdevices did not appear within timeout")
 
     def remove(self):
-        self.ctrl_write("del_device", "%u" % (self.addr, ))
+        if not self.removed:
+            self.ctrl_write("del_device", "%u" % (self.addr, ))
+            self.removed = True
 
     def remove_nsim(self, nsim):
         self.nsims.remove(nsim)