diff --git a/src/wifi/test/tx-duration-test.cc b/src/wifi/test/tx-duration-test.cc
index 2546557d7..63ed492ca 100644
--- a/src/wifi/test/tx-duration-test.cc
+++ b/src/wifi/test/tx-duration-test.cc
@@ -1474,6 +1474,7 @@ class HeSigBDurationTest : public TestCase
 
   private:
     void DoRun() override;
+    void DoTeardown() override;
 
     /**
      * Build a TXVECTOR for HE MU.
@@ -1482,6 +1483,8 @@ class HeSigBDurationTest : public TestCase
      */
     WifiTxVector BuildTxVector() const;
 
+    Ptr<YansWifiPhy> m_phy; ///< the PHY under test
+
     std::list<HeMuUserInfo> m_userInfos; ///< HE MU specific per-user information
     WifiMode m_sigBMode;                 ///< Mode used to transmit HE-SIG-B
     MHz_u m_channelWidth;                ///< Channel width
@@ -1538,19 +1541,19 @@ HeSigBDurationTest::BuildTxVector() const
 void
 HeSigBDurationTest::DoRun()
 {
-    auto phy = CreateObject<YansWifiPhy>();
+    m_phy = CreateObject<YansWifiPhy>();
     auto channelNum = WifiPhyOperatingChannel::FindFirst(0,
                                                          MHz_u{0},
                                                          MHz_u{160},
                                                          WIFI_STANDARD_80211ax,
                                                          WIFI_PHY_BAND_6GHZ)
                           ->number;
-    phy->SetOperatingChannel(
+    m_phy->SetOperatingChannel(
         WifiPhy::ChannelTuple{channelNum, 160, WIFI_PHY_BAND_6GHZ, m_p20Index});
-    phy->ConfigureStandard(WIFI_STANDARD_80211ax);
+    m_phy->ConfigureStandard(WIFI_STANDARD_80211ax);
 
     const auto& txVector = BuildTxVector();
-    const auto& hePhy = phy->GetPhyEntity(WIFI_MOD_CLASS_HE);
+    const auto& hePhy = m_phy->GetPhyEntity(WIFI_MOD_CLASS_HE);
 
     // Verify mode for HE-SIG-B field
     NS_TEST_EXPECT_MSG_EQ(hePhy->GetSigMode(WIFI_PPDU_FIELD_SIG_B, txVector),
@@ -1597,7 +1600,7 @@ HeSigBDurationTest::DoRun()
         auto psdu = Create<WifiPsdu>(Create<Packet>(1000), hdr);
         ppduDuration = std::max(
             ppduDuration,
-            WifiPhy::CalculateTxDuration(psdu->GetSize(), txVector, phy->GetPhyBand(), i + 1));
+            WifiPhy::CalculateTxDuration(psdu->GetSize(), txVector, m_phy->GetPhyBand(), i + 1));
         psdus.insert(std::make_pair(i, psdu));
     }
     auto ppdu = hePhy->BuildPpdu(psdus, txVector, ppduDuration);
@@ -1606,6 +1609,15 @@ HeSigBDurationTest::DoRun()
     NS_TEST_EXPECT_MSG_EQ((txVector.GetHeMuUserInfoMap() == rxVector.GetHeMuUserInfoMap()),
                           true,
                           "Incorrect user infos in reconstructed TXVECTOR");
+
+    Simulator::Destroy();
+}
+
+void
+HeSigBDurationTest::DoTeardown()
+{
+    m_phy->Dispose();
+    m_phy = nullptr;
 }
 
 /**