diff --git a/BUILD.gn b/BUILD.gn
index a9ab6783fa..bc8455ce64 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -5202,6 +5202,7 @@ if (is_component_build) {

     public_deps = [
       ":v8_base",
+      ":v8_initializers",
       ":v8_snapshot",
     ]

diff --git a/src/codegen/code-stub-assembler.h b/src/codegen/code-stub-assembler.h
index 03af2cc5e2..bb19092c54 100644
--- a/src/codegen/code-stub-assembler.h
+++ b/src/codegen/code-stub-assembler.h
@@ -301,7 +301,7 @@ enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };
 // it's possible to add JavaScript-specific useful CodeAssembler "macros"
 // without modifying files in the compiler directory (and requiring a review
 // from a compiler directory OWNER).
-class V8_EXPORT_PRIVATE CodeStubAssembler
+class V8_EXPORT CodeStubAssembler
     : public compiler::CodeAssembler,
       public TorqueGeneratedExportedMacrosAssembler {
  public:
diff --git a/src/common/globals.h b/src/common/globals.h
index d9d502aa51..7495c898fc 100644
--- a/src/common/globals.h
+++ b/src/common/globals.h
@@ -1348,7 +1348,7 @@ class BinaryOperationFeedback {
 // This is distinct from BinaryOperationFeedback on purpose, because the
 // feedback that matters differs greatly as well as the way it is consumed.
 class CompareOperationFeedback {
-  enum {
+  enum : uint32_t {
     kSignedSmallFlag = 1 << 0,
     kOtherNumberFlag = 1 << 1,
     kBooleanFlag = 1 << 2,
@@ -1362,7 +1362,7 @@ class CompareOperationFeedback {
   };

  public:
-  enum Type {
+  enum Type : uint32_t {
     kNone = 0,

     kBoolean = kBooleanFlag,
diff --git a/src/compiler/node-cache.h b/src/compiler/node-cache.h
index 8e1d3d4eae..c55d8329de 100644
--- a/src/compiler/node-cache.h
+++ b/src/compiler/node-cache.h
@@ -29,7 +29,7 @@ class Node;
 // nodes such as constants, parameters, etc.
 template <typename Key, typename Hash = base::hash<Key>,
           typename Pred = std::equal_to<Key> >
-class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) NodeCache final {
+class V8_EXPORT_PRIVATE NodeCache final {
  public:
   explicit NodeCache(Zone* zone) : map_(zone) {}
   ~NodeCache() = default;
diff --git a/src/heap/paged-spaces-inl.h b/src/heap/paged-spaces-inl.h
index e135e30efc..0c055247bc 100644
--- a/src/heap/paged-spaces-inl.h
+++ b/src/heap/paged-spaces-inl.h
@@ -19,7 +19,7 @@ namespace internal {
 // -----------------------------------------------------------------------------
 // PagedSpaceObjectIterator

-HeapObject PagedSpaceObjectIterator::Next() {
+inline HeapObject PagedSpaceObjectIterator::Next() {
   do {
     HeapObject next_obj = FromCurrentPage();
     if (!next_obj.is_null()) return next_obj;
diff --git a/src/heap/paged-spaces.h b/src/heap/paged-spaces.h
index 5168f0f053..ae5c22d1f3 100644
--- a/src/heap/paged-spaces.h
+++ b/src/heap/paged-spaces.h
@@ -45,7 +45,7 @@ class V8_EXPORT_PRIVATE PagedSpaceObjectIterator : public ObjectIterator {
   // Advance to the next object, skipping free spaces and other fillers and
   // skipping the special garbage section of which there is one per space.
   // Returns nullptr when the iteration has ended.
-  inline HeapObject Next() override;
+  HeapObject Next() override;

  private:
   // Fast (inlined) path of next().
diff --git a/src/objects/feedback-vector.cc b/src/objects/feedback-vector.cc
index a77ea5d265..0cddb92a02 100644
--- a/src/objects/feedback-vector.cc
+++ b/src/objects/feedback-vector.cc
@@ -114,9 +114,9 @@ Handle<FeedbackMetadata> FeedbackMetadata::New(LocalIsolate* isolate,
   return metadata;
 }

-template Handle<FeedbackMetadata> FeedbackMetadata::New(
+template V8_EXPORT Handle<FeedbackMetadata> FeedbackMetadata::New(
     Isolate* isolate, const FeedbackVectorSpec* spec);
-template Handle<FeedbackMetadata> FeedbackMetadata::New(
+template V8_EXPORT Handle<FeedbackMetadata> FeedbackMetadata::New(
     LocalIsolate* isolate, const FeedbackVectorSpec* spec);

 bool FeedbackMetadata::SpecDiffersFrom(
diff --git a/src/objects/fixed-array-inl.h b/src/objects/fixed-array-inl.h
index a91f89784f..5ecf7e3372 100644
--- a/src/objects/fixed-array-inl.h
+++ b/src/objects/fixed-array-inl.h
@@ -88,7 +88,7 @@ bool FixedArray::is_the_hole(Isolate* isolate, int index) {
   return get(isolate, index).IsTheHole(isolate);
 }

-void FixedArray::set(int index, Smi value) {
+inline V8_EXPORT_PRIVATE void FixedArray::set(int index, Smi value) {
   DCHECK_NE(map(), GetReadOnlyRoots().fixed_cow_array_map());
   DCHECK_LT(static_cast<unsigned>(index), static_cast<unsigned>(length()));
   DCHECK(Object(value).IsSmi());
diff --git a/src/objects/fixed-array.h b/src/objects/fixed-array.h
index 53b4cbb22b..8dd24df399 100644
--- a/src/objects/fixed-array.h
+++ b/src/objects/fixed-array.h
@@ -130,7 +130,7 @@ class FixedArray
   inline bool is_the_hole(Isolate* isolate, int index);

   // Setter that doesn't need write barrier.
-  inline void set(int index, Smi value);
+  inline V8_EXPORT_PRIVATE void set(int index, Smi value);
   // Setter with explicit barrier mode.
   inline void set(int index, Object value, WriteBarrierMode mode);

diff --git a/src/runtime/runtime-wasm.cc b/src/runtime/runtime-wasm.cc
index 9ba26c23ad..5857bf4c39 100644
--- a/src/runtime/runtime-wasm.cc
+++ b/src/runtime/runtime-wasm.cc
@@ -570,7 +570,7 @@ RUNTIME_FUNCTION(Runtime_WasmDebugBreak) {
   DebugScope debug_scope(isolate->debug());

   // Check for instrumentation breakpoint.
-  DCHECK_EQ(script->break_on_entry(), instance->break_on_entry());
+  DCHECK_EQ(script->break_on_entry(), static_cast<bool>(instance->break_on_entry()));
   if (script->break_on_entry()) {
     MaybeHandle<FixedArray> maybe_on_entry_breakpoints =
         WasmScript::CheckBreakPoints(
diff --git a/src/snapshot/snapshot-utils.cc b/src/snapshot/snapshot-utils.cc
index eb2372372c..7defadb4b1 100644
--- a/src/snapshot/snapshot-utils.cc
+++ b/src/snapshot/snapshot-utils.cc
@@ -5,7 +5,7 @@
 #include "src/snapshot/snapshot-utils.h"

 #include "src/sanitizer/msan.h"
-#include "third_party/zlib/zlib.h"
+#include "zlib.h"

 namespace v8 {
 namespace internal {
diff --git a/src/wasm/function-body-decoder-impl.h b/src/wasm/function-body-decoder-impl.h
index 6c9700b100..e3be3c31f5 100644
--- a/src/wasm/function-body-decoder-impl.h
+++ b/src/wasm/function-body-decoder-impl.h
@@ -2006,7 +2006,7 @@ class WasmDecoder : public Decoder {
   }

   // TODO(clemensb): This is only used by the interpreter; move there.
-  V8_EXPORT_PRIVATE std::pair<uint32_t, uint32_t> StackEffect(const byte* pc) {
+  std::pair<uint32_t, uint32_t> StackEffect(const byte* pc) {
     WasmOpcode opcode = static_cast<WasmOpcode>(*pc);
     // Handle "simple" opcodes with a fixed signature first.
     const FunctionSig* sig = WasmOpcodes::Signature(opcode);
diff --git a/test/cctest/BUILD.gn b/test/cctest/BUILD.gn
index e63fe5ed35..ec48403c42 100644
--- a/test/cctest/BUILD.gn
+++ b/test/cctest/BUILD.gn
@@ -480,6 +480,10 @@ v8_source_set("cctest_sources") {
     # C4309: 'static_cast': truncation of constant value
     cflags += [ "/wd4309" ]

+    if(!is_clang) {
+      cflags += [ "/wd4789" ]
+    }
+
     # MSVS wants this for gay-{precision,shortest}.cc.
     cflags += [ "/bigobj" ]

diff --git a/tools/debug_helper/BUILD.gn b/tools/debug_helper/BUILD.gn
index 54cd3b7a4c..9c6666871d 100644
--- a/tools/debug_helper/BUILD.gn
+++ b/tools/debug_helper/BUILD.gn
@@ -99,10 +99,12 @@ v8_component("v8_debug_helper") {
     "../..:v8_libbase",
     "../..:v8_shared_internal_headers",
     "../..:v8_tracing",
+    "../..:v8",
   ]

   configs = [ ":internal_config" ]
   if (v8_enable_i18n_support) {
+    public_deps = [ "//third_party/icu" ]
     configs += [ "//third_party/icu:icu_config" ]
   }

diff --git a/tools/v8windbg/BUILD.gn b/tools/v8windbg/BUILD.gn
index 10d06a127f..d0deb7adca 100644
--- a/tools/v8windbg/BUILD.gn
+++ b/tools/v8windbg/BUILD.gn
@@ -6,7 +6,7 @@ import("../../gni/v8.gni")

 config("v8windbg_config") {
   # Required for successful compilation of SDK header file DbgModel.h.
-  cflags_cc = [ "/Zc:twoPhase-" ]
+  cflags_cc = [ "/Zc:twoPhase-", "/std:c++latest" ]

   include_dirs = [ "../.." ]
 }
diff --git a/tools/v8windbg/base/dbgext.h b/tools/v8windbg/base/dbgext.h
index 8b36a8f361..f8d9f0d64e 100644
--- a/tools/v8windbg/base/dbgext.h
+++ b/tools/v8windbg/base/dbgext.h
@@ -9,6 +9,7 @@
 #error Unicode not defined
 #endif

+#include <new>
 #include <DbgEng.h>
 #include <DbgModel.h>
 #include <Windows.h>
diff --git a/tools/v8windbg/src/v8-debug-helper-interop.h b/tools/v8windbg/src/v8-debug-helper-interop.h
index f7d78c5dd3..1c70e54e7a 100644
--- a/tools/v8windbg/src/v8-debug-helper-interop.h
+++ b/tools/v8windbg/src/v8-debug-helper-interop.h
@@ -5,10 +5,11 @@
 #ifndef V8_TOOLS_V8WINDBG_SRC_V8_DEBUG_HELPER_INTEROP_H_
 #define V8_TOOLS_V8WINDBG_SRC_V8_DEBUG_HELPER_INTEROP_H_

-#include <wrl/client.h>
-
+#include <new>
+#include <DbgEng.h>
 #include <DbgModel.h>

+#include <wrl/client.h>
 #include <cstdint>
 #include <map>
 #include <string>
diff --git a/tools/v8windbg/test/debug-callbacks.h b/tools/v8windbg/test/debug-callbacks.h
index 8855d6ffbc..ed2b0f62e9 100644
--- a/tools/v8windbg/test/debug-callbacks.h
+++ b/tools/v8windbg/test/debug-callbacks.h
@@ -9,6 +9,7 @@
 #error Unicode not defined
 #endif

+#include <new>
 #include <DbgEng.h>
 #include <DbgModel.h>
 #include <Windows.h>