diff --git a/iocore/net/UnixNet.cc b/iocore/net/UnixNet.cc
index eb95841f934..76a10a46620 100644
--- a/iocore/net/UnixNet.cc
+++ b/iocore/net/UnixNet.cc
@@ -673,6 +673,7 @@ void
 NetHandler::add_to_keep_alive_queue(UnixNetVConnection *vc)
 {
   Debug("net_queue", "NetVC: %p", vc);
+  ink_assert(mutex->thread_holding == this_ethread());
 
   if (keep_alive_queue.in(vc)) {
     // already in the keep-alive queue, move the head
@@ -692,6 +693,8 @@ void
 NetHandler::remove_from_keep_alive_queue(UnixNetVConnection *vc)
 {
   Debug("net_queue", "NetVC: %p", vc);
+  ink_assert(mutex->thread_holding == this_ethread());
+
   if (keep_alive_queue.in(vc)) {
     keep_alive_queue.remove(vc);
     --keep_alive_queue_size;
@@ -704,6 +707,7 @@ NetHandler::add_to_active_queue(UnixNetVConnection *vc)
   Debug("net_queue", "NetVC: %p", vc);
   Debug("net_queue", "max_connections_per_thread_in: %d active_queue_size: %d keep_alive_queue_size: %d",
         max_connections_per_thread_in, active_queue_size, keep_alive_queue_size);
+  ink_assert(mutex->thread_holding == this_ethread());
 
   // if active queue is over size then close inactive connections
   if (manage_active_queue() == false) {
@@ -728,6 +732,8 @@ void
 NetHandler::remove_from_active_queue(UnixNetVConnection *vc)
 {
   Debug("net_queue", "NetVC: %p", vc);
+  ink_assert(mutex->thread_holding == this_ethread());
+
   if (active_queue.in(vc)) {
     active_queue.remove(vc);
     --active_queue_size;
diff --git a/iocore/net/UnixNetVConnection.cc b/iocore/net/UnixNetVConnection.cc
index e01fc57f31a..9166462f362 100644
--- a/iocore/net/UnixNetVConnection.cc
+++ b/iocore/net/UnixNetVConnection.cc
@@ -1481,25 +1481,48 @@ UnixNetVConnection::migrateToCurrentThread(Continuation *cont, EThread *t)
 void
 UnixNetVConnection::add_to_keep_alive_queue()
 {
-  nh->add_to_keep_alive_queue(this);
+  MUTEX_TRY_LOCK(lock, nh->mutex, this_ethread());
+  if (lock.is_locked()) {
+    nh->add_to_keep_alive_queue(this);
+  } else {
+    ink_release_assert(!"BUG: It must have acquired the NetHandler's lock before doing anything on keep_alive_queue.");
+  }
 }
 
 void
 UnixNetVConnection::remove_from_keep_alive_queue()
 {
-  nh->remove_from_keep_alive_queue(this);
+  MUTEX_TRY_LOCK(lock, nh->mutex, this_ethread());
+  if (lock.is_locked()) {
+    nh->remove_from_keep_alive_queue(this);
+  } else {
+    ink_release_assert(!"BUG: It must have acquired the NetHandler's lock before doing anything on keep_alive_queue.");
+  }
 }
 
 bool
 UnixNetVConnection::add_to_active_queue()
 {
-  return nh->add_to_active_queue(this);
+  bool result = false;
+
+  MUTEX_TRY_LOCK(lock, nh->mutex, this_ethread());
+  if (lock.is_locked()) {
+    result = nh->add_to_active_queue(this);
+  } else {
+    ink_release_assert(!"BUG: It must have acquired the NetHandler's lock before doing anything on active_queue.");
+  }
+  return result;
 }
 
 void
 UnixNetVConnection::remove_from_active_queue()
 {
-  nh->remove_from_active_queue(this);
+  MUTEX_TRY_LOCK(lock, nh->mutex, this_ethread());
+  if (lock.is_locked()) {
+    nh->remove_from_active_queue(this);
+  } else {
+    ink_release_assert(!"BUG: It must have acquired the NetHandler's lock before doing anything on active_queue.");
+  }
 }
 
 int