diff --git a/netwerk/protocol/http/nsHttpConnectionMgr.cpp b/netwerk/protocol/http/nsHttpConnectionMgr.cpp
index a76b06044f06..7077794c394a 100644
--- a/netwerk/protocol/http/nsHttpConnectionMgr.cpp
+++ b/netwerk/protocol/http/nsHttpConnectionMgr.cpp
@@ -4030,6 +4030,7 @@ nsHalfOpenSocket::OnOutputStreamReady(nsIAsyncOutputStream *out)
         mFastOpenInProgress = false;
         mConnectionNegotiatingFastOpen = nullptr;
     }
+    MOZ_DIAGNOSTIC_ASSERT(mEnt);
     nsresult rv =  SetupConn(out, false);
     if (mEnt) {
         mEnt->mDoNotDestroy = false;
@@ -4043,6 +4044,8 @@ nsHalfOpenSocket::FastOpenEnabled()
 {
     LOG(("nsHalfOpenSocket::FastOpenEnabled [this=%p]\n", this));
 
+    MOZ_DIAGNOSTIC_ASSERT(mEnt);
+
     if (!mEnt) {
         return false;
     }
@@ -4534,6 +4537,7 @@ nsHttpConnectionMgr::nsHalfOpenSocket::OnTransportStatus(nsITransport *trans,
 {
     MOZ_ASSERT(OnSocketThread(), "not on socket thread");
 
+    MOZ_DIAGNOSTIC_ASSERT(mEnt);
     if (mTransaction) {
         RefPtr<PendingTransactionInfo> info = FindTransactionHelper(false);
         if ((trans == mSocketTransport) ||
diff --git a/netwerk/protocol/http/nsHttpConnectionMgr.h b/netwerk/protocol/http/nsHttpConnectionMgr.h
index 7a1feee8df35..4feca8af02b7 100644
--- a/netwerk/protocol/http/nsHttpConnectionMgr.h
+++ b/netwerk/protocol/http/nsHttpConnectionMgr.h
@@ -244,9 +244,10 @@ private:
     // contains list of active and idle connections as well as the list of
     // pending transactions.
     //
-    class nsConnectionEntry
+    class nsConnectionEntry : public SupportsWeakPtr<nsConnectionEntry>
     {
     public:
+        MOZ_DECLARE_WEAKREFERENCE_TYPENAME(nsConnectionEntry)
         explicit nsConnectionEntry(nsHttpConnectionInfo *ci);
         ~nsConnectionEntry();
 
@@ -415,7 +416,7 @@ private:
         already_AddRefed<PendingTransactionInfo>
         FindTransactionHelper(bool removeWhenFound);
 
-        nsConnectionEntry             *mEnt;
+        WeakPtr<nsConnectionEntry>     mEnt;
         RefPtr<nsAHttpTransaction>     mTransaction;
         bool                           mDispatchedMTransaction;
         nsCOMPtr<nsISocketTransport>   mSocketTransport;