diff --git a/src/httpserver.cpp b/src/httpserver.cpp
index 216fc81179..21b3bd0904 100644
--- a/src/httpserver.cpp
+++ b/src/httpserver.cpp
@@ -482,6 +482,7 @@ void StopHTTPServer()
         workQueue->WaitExit();
 #endif        
         delete workQueue;
+        workQueue = nullptr;
     }
     if (eventBase) {
         LogPrint("http", "Waiting for HTTP event thread to exit\n");
diff --git a/src/qt/test/rpcnestedtests.cpp b/src/qt/test/rpcnestedtests.cpp
index 30b9c92330..cacfa5f69d 100644
--- a/src/qt/test/rpcnestedtests.cpp
+++ b/src/qt/test/rpcnestedtests.cpp
@@ -160,11 +160,13 @@ void RPCNestedTests::rpcNestedTests()
     pcoinsTip = nullptr;
     llmq::DestroyLLMQSystem();
     delete deterministicMNManager;
+    deterministicMNManager = nullptr;
     delete pcoinsdbview;
     pcoinsdbview = nullptr;
     delete pblocktree;
     pblocktree = nullptr;
     delete evoDb;
+    evoDb = nullptr;
 
     boost::filesystem::remove_all(boost::filesystem::path(path));
 }
diff --git a/src/test/dbwrapper_tests.cpp b/src/test/dbwrapper_tests.cpp
index ca55dccf42..371d103c7d 100644
--- a/src/test/dbwrapper_tests.cpp
+++ b/src/test/dbwrapper_tests.cpp
@@ -141,6 +141,7 @@ BOOST_AUTO_TEST_CASE(existing_data_no_obfuscate)
 
     // Call the destructor to free leveldb LOCK
     delete dbw;
+    dbw = nullptr;
 
     // Now, set up another wrapper that wants to obfuscate the same directory
     CDBWrapper odbw(ph, (1 << 10), false, false, true);
@@ -182,6 +183,7 @@ BOOST_AUTO_TEST_CASE(existing_data_reindex)
 
     // Call the destructor to free leveldb LOCK
     delete dbw;
+    dbw = nullptr;
 
     // Simulate a -reindex by wiping the existing data store
     CDBWrapper odbw(ph, (1 << 10), false, true, true);