diff --git a/src/net_processing.h b/src/net_processing.h
index cdc578b34a7d83..a5aa48130a9173 100644
--- a/src/net_processing.h
+++ b/src/net_processing.h
@@ -58,7 +58,7 @@ class PeerLogicValidation : public CValidationInterface, public NetEventsInterfa
     * @param[in]   interrupt       Interrupt condition for processing threads
     * @return                      True if there is more work to be done
     */
-    bool SendMessages(CNode* pto, std::atomic<bool>& interrupt) override;
+    bool SendMessages(CNode* pto, std::atomic<bool>& interrupt) override EXCLUSIVE_LOCKS_REQUIRED(pto->cs_sendProcessing);
 
     /** Consider evicting an outbound peer based on the amount of time they've been behind our tip */
     void ConsiderEviction(CNode *pto, int64_t time_in_seconds);
diff --git a/src/test/denialofservice_tests.cpp b/src/test/denialofservice_tests.cpp
index aa8cbf448b6a74..ee0493dcce93b2 100644
--- a/src/test/denialofservice_tests.cpp
+++ b/src/test/denialofservice_tests.cpp
@@ -69,26 +69,41 @@ BOOST_AUTO_TEST_CASE(outbound_slow_chain_eviction)
     dummyNode1.fSuccessfullyConnected = true;
 
     // This test requires that we have a chain with non-zero work.
-    LOCK(cs_main);
-    BOOST_CHECK(chainActive.Tip() != nullptr);
-    BOOST_CHECK(chainActive.Tip()->nChainWork > 0);
+    {
+        LOCK(cs_main);
+        BOOST_CHECK(chainActive.Tip() != nullptr);
+        BOOST_CHECK(chainActive.Tip()->nChainWork > 0);
+    }
 
     // Test starts here
-    LOCK(dummyNode1.cs_sendProcessing);
-    peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in getheaders
-    LOCK(dummyNode1.cs_vSend);
-    BOOST_CHECK(dummyNode1.vSendMsg.size() > 0);
-    dummyNode1.vSendMsg.clear();
-    dummyNode1.nSendMsgSize = 0;
+    {
+        LOCK2(cs_main, dummyNode1.cs_sendProcessing);
+        peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in getheaders
+    }
+    {
+        LOCK2(cs_main, dummyNode1.cs_vSend);
+        BOOST_CHECK(dummyNode1.vSendMsg.size() > 0);
+        dummyNode1.vSendMsg.clear();
+        dummyNode1.nSendMsgSize = 0;
+    }
 
     int64_t nStartTime = GetTime();
     // Wait 21 minutes
     SetMockTime(nStartTime+21*60);
-    peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in getheaders
-    BOOST_CHECK(dummyNode1.vSendMsg.size() > 0);
+    {
+        LOCK2(cs_main, dummyNode1.cs_sendProcessing);
+        peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in getheaders
+    }
+    {
+        LOCK2(cs_main, dummyNode1.cs_vSend);
+        BOOST_CHECK(dummyNode1.vSendMsg.size() > 0);
+    }
     // Wait 3 more minutes
     SetMockTime(nStartTime+24*60);
-    peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in disconnect
+    {
+        LOCK2(cs_main, dummyNode1.cs_sendProcessing);
+        peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in disconnect
+    }
     BOOST_CHECK(dummyNode1.fDisconnect == true);
     SetMockTime(0);
 
@@ -194,8 +209,10 @@ BOOST_AUTO_TEST_CASE(DoS_banning)
         LOCK(cs_main);
         Misbehaving(dummyNode1.GetId(), 100); // Should get banned
     }
-    LOCK(dummyNode1.cs_sendProcessing);
-    peerLogic->SendMessages(&dummyNode1, interruptDummy);
+    {
+        LOCK2(cs_main, dummyNode1.cs_sendProcessing);
+        peerLogic->SendMessages(&dummyNode1, interruptDummy);
+    }
     BOOST_CHECK(connman->IsBanned(addr1));
     BOOST_CHECK(!connman->IsBanned(ip(0xa0b0c001|0x0000ff00))); // Different IP, not banned
 
@@ -209,15 +226,20 @@ BOOST_AUTO_TEST_CASE(DoS_banning)
         LOCK(cs_main);
         Misbehaving(dummyNode2.GetId(), 50);
     }
-    LOCK(dummyNode2.cs_sendProcessing);
-    peerLogic->SendMessages(&dummyNode2, interruptDummy);
+    {
+        LOCK2(cs_main, dummyNode2.cs_sendProcessing);
+        peerLogic->SendMessages(&dummyNode2, interruptDummy);
+    }
     BOOST_CHECK(!connman->IsBanned(addr2)); // 2 not banned yet...
     BOOST_CHECK(connman->IsBanned(addr1));  // ... but 1 still should be
     {
         LOCK(cs_main);
         Misbehaving(dummyNode2.GetId(), 50);
     }
-    peerLogic->SendMessages(&dummyNode2, interruptDummy);
+    {
+        LOCK2(cs_main, dummyNode2.cs_sendProcessing);
+        peerLogic->SendMessages(&dummyNode2, interruptDummy);
+    }
     BOOST_CHECK(connman->IsBanned(addr2));
 
     bool dummy;
@@ -241,20 +263,28 @@ BOOST_AUTO_TEST_CASE(DoS_banscore)
         LOCK(cs_main);
         Misbehaving(dummyNode1.GetId(), 100);
     }
-    LOCK(dummyNode1.cs_sendProcessing);
-    peerLogic->SendMessages(&dummyNode1, interruptDummy);
+    {
+        LOCK2(cs_main, dummyNode1.cs_sendProcessing);
+        peerLogic->SendMessages(&dummyNode1, interruptDummy);
+    }
     BOOST_CHECK(!connman->IsBanned(addr1));
     {
         LOCK(cs_main);
         Misbehaving(dummyNode1.GetId(), 10);
     }
-    peerLogic->SendMessages(&dummyNode1, interruptDummy);
+    {
+        LOCK2(cs_main, dummyNode1.cs_sendProcessing);
+        peerLogic->SendMessages(&dummyNode1, interruptDummy);
+    }
     BOOST_CHECK(!connman->IsBanned(addr1));
     {
         LOCK(cs_main);
         Misbehaving(dummyNode1.GetId(), 1);
     }
-    peerLogic->SendMessages(&dummyNode1, interruptDummy);
+    {
+        LOCK2(cs_main, dummyNode1.cs_sendProcessing);
+        peerLogic->SendMessages(&dummyNode1, interruptDummy);
+    }
     BOOST_CHECK(connman->IsBanned(addr1));
     gArgs.ForceSetArg("-banscore", std::to_string(DEFAULT_BANSCORE_THRESHOLD));
 
@@ -281,8 +311,10 @@ BOOST_AUTO_TEST_CASE(DoS_bantime)
         LOCK(cs_main);
         Misbehaving(dummyNode.GetId(), 100);
     }
-    LOCK(dummyNode.cs_sendProcessing);
-    peerLogic->SendMessages(&dummyNode, interruptDummy);
+    {
+        LOCK2(cs_main, dummyNode.cs_sendProcessing);
+        peerLogic->SendMessages(&dummyNode, interruptDummy);
+    }
     BOOST_CHECK(connman->IsBanned(addr));
 
     SetMockTime(nStartTime+60*60);