diff --git a/src/wifi/model/channel-access-manager.cc b/src/wifi/model/channel-access-manager.cc
index 6afcc8456..d83a8783a 100644
--- a/src/wifi/model/channel-access-manager.cc
+++ b/src/wifi/model/channel-access-manager.cc
@@ -730,8 +730,10 @@ ChannelAccessManager::NotifyCcaBusyStartNow(Time duration,
     NS_ASSERT(lastBusyEndIt != m_lastBusyEnd.end());
     Time now = Simulator::Now();
     lastBusyEndIt->second = now + duration;
-    // TODO uncomment assert below when PHY passes correct parameters
-    // NS_ASSERT (per20MhzDurations.size () == m_lastPer20MHzBusyEnd.size ());
+    NS_ASSERT_MSG(per20MhzDurations.size() == m_lastPer20MHzBusyEnd.size(),
+                  "Size of received vector (" << per20MhzDurations.size()
+                                              << ") differs from the expected size ("
+                                              << m_lastPer20MHzBusyEnd.size() << ")");
     for (std::size_t chIdx = 0; chIdx < per20MhzDurations.size(); ++chIdx)
     {
         if (per20MhzDurations[chIdx].IsStrictlyPositive())
diff --git a/src/wifi/test/channel-access-manager-test.cc b/src/wifi/test/channel-access-manager-test.cc
index 0eda79947..601f31114 100644
--- a/src/wifi/test/channel-access-manager-test.cc
+++ b/src/wifi/test/channel-access-manager-test.cc
@@ -1381,7 +1381,7 @@ LargestIdlePrimaryChannelTest::RunOne(uint16_t chWidth, WifiChannelListType busy
                         m_cam,
                         ccaBusyDuration,
                         busyChannel,
-                        std::vector<Time>(chWidth / 20, Seconds(0)));
+                        std::vector<Time>(chWidth == 20 ? 0 : chWidth / 20, Seconds(0)));
 
     // During any interval ending within CCA_BUSY period, the idle channel is the
     // primary channel contiguous to the busy secondary channel, if the busy channel