diff --git a/.appveyor.yml b/.appveyor.yml
index 2aebf1cd542..249d0b8df98 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -33,7 +33,7 @@ before_build:
 - ps:  Start-Process clcache-server
 - ps:  fsutil behavior set disablelastaccess 0 # Enable Access time feature on Windows (for clcache)
 build_script:
-- cmd: msbuild /p:TrackFileAccess=false /p:CLToolExe=clcache.exe build_msvc\bitcoin.sln /m /v:q /nowarn:C4244;C4267;C4715 /nologo
+- cmd: msbuild /p:TrackFileAccess=false /p:CLToolExe=clcache.exe build_msvc\bitcoin.sln /m /v:q /nologo
 after_build:
 - ps:  fsutil behavior set disablelastaccess 1 # Disable Access time feature on Windows (better performance)
 - ps:  clcache -z
diff --git a/build_msvc/common.vcxproj b/build_msvc/common.vcxproj
index 5c87026efe6..c7c20622e43 100644
--- a/build_msvc/common.vcxproj
+++ b/build_msvc/common.vcxproj
@@ -15,6 +15,8 @@
   <ItemDefinitionGroup>
     <ClCompile>
       <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
+      <DisableSpecificWarnings>4018;4244;4267;4715;4805;</DisableSpecificWarnings>
+      <TreatWarningAsError>true</TreatWarningAsError>
     </ClCompile>
   </ItemDefinitionGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/test/allocator_tests.cpp b/src/test/allocator_tests.cpp
index 5a108dcdadf..582082f6a48 100644
--- a/src/test/allocator_tests.cpp
+++ b/src/test/allocator_tests.cpp
@@ -144,7 +144,7 @@ public:
                 *lockingSuccess = true;
             }
 
-            return reinterpret_cast<void*>(0x08000000 + (count<<24)); // Fake address, do not actually use this memory
+            return reinterpret_cast<void*>(uint64_t{static_cast<uint64_t>(0x08000000) + (count << 24)}); // Fake address, do not actually use this memory
         }
         return 0;
     }
diff --git a/src/test/crypto_tests.cpp b/src/test/crypto_tests.cpp
index f3fd83a0cc0..86cb00a78f0 100644
--- a/src/test/crypto_tests.cpp
+++ b/src/test/crypto_tests.cpp
@@ -532,7 +532,7 @@ BOOST_AUTO_TEST_CASE(countbits_tests)
             // Check handling of zero.
             BOOST_CHECK_EQUAL(CountBits(0), 0U);
         } else if (i < 10) {
-            for (uint64_t j = 1 << (i - 1); (j >> i) == 0; ++j) {
+            for (uint64_t j = (uint64_t)1 << (i - 1); (j >> i) == 0; ++j) {
                 // Exhaustively test up to 10 bits
                 BOOST_CHECK_EQUAL(CountBits(j), i);
             }
diff --git a/src/test/script_tests.cpp b/src/test/script_tests.cpp
index 1b394753efb..87c3e74df0c 100644
--- a/src/test/script_tests.cpp
+++ b/src/test/script_tests.cpp
@@ -184,11 +184,12 @@ void DoTest(const CScript& scriptPubKey, const CScript& scriptSig, const CScript
     stream << tx2;
     int libconsensus_flags = flags & bitcoinconsensus_SCRIPT_FLAGS_VERIFY_ALL;
     if (libconsensus_flags == flags) {
+        int expectedSuccessCode = expect ? 1 : 0;
         if (flags & bitcoinconsensus_SCRIPT_FLAGS_VERIFY_WITNESS) {
-            BOOST_CHECK_MESSAGE(bitcoinconsensus_verify_script_with_amount(scriptPubKey.data(), scriptPubKey.size(), txCredit.vout[0].nValue, (const unsigned char*)&stream[0], stream.size(), 0, libconsensus_flags, nullptr) == expect, message);
+            BOOST_CHECK_MESSAGE(bitcoinconsensus_verify_script_with_amount(scriptPubKey.data(), scriptPubKey.size(), txCredit.vout[0].nValue, (const unsigned char*)&stream[0], stream.size(), 0, libconsensus_flags, nullptr) == expectedSuccessCode, message);
         } else {
-            BOOST_CHECK_MESSAGE(bitcoinconsensus_verify_script_with_amount(scriptPubKey.data(), scriptPubKey.size(), 0, (const unsigned char*)&stream[0], stream.size(), 0, libconsensus_flags, nullptr) == expect, message);
-            BOOST_CHECK_MESSAGE(bitcoinconsensus_verify_script(scriptPubKey.data(), scriptPubKey.size(), (const unsigned char*)&stream[0], stream.size(), 0, libconsensus_flags, nullptr) == expect,message);
+            BOOST_CHECK_MESSAGE(bitcoinconsensus_verify_script_with_amount(scriptPubKey.data(), scriptPubKey.size(), 0, (const unsigned char*)&stream[0], stream.size(), 0, libconsensus_flags, nullptr) == expectedSuccessCode, message);
+            BOOST_CHECK_MESSAGE(bitcoinconsensus_verify_script(scriptPubKey.data(), scriptPubKey.size(), (const unsigned char*)&stream[0], stream.size(), 0, libconsensus_flags, nullptr) == expectedSuccessCode, message);
         }
     }
 #endif