diff --git a/cmake/targets/BuildBun.cmake b/cmake/targets/BuildBun.cmake
index f9b60e2dff..60958ceaf2 100644
--- a/cmake/targets/BuildBun.cmake
+++ b/cmake/targets/BuildBun.cmake
@@ -747,6 +747,18 @@ set_target_properties(${bun} PROPERTIES
   VISIBILITY_INLINES_HIDDEN YES
 )
 
+if (NOT WIN32)
+  # Enable precompiled headers
+  # Only enable in these scenarios:
+  # 1. NOT in CI, OR
+  # 2. In CI AND BUN_CPP_ONLY is enabled
+  if(NOT CI OR (CI AND BUN_CPP_ONLY))
+    target_precompile_headers(${bun} PRIVATE
+      "$<$<COMPILE_LANGUAGE:CXX>:${CWD}/src/bun.js/bindings/root.h>"
+    )
+  endif()
+endif()
+
 # --- C/C++ Includes ---
 
 if(WIN32)
@@ -901,6 +913,10 @@ if(NOT WIN32)
       -Werror
     )
   endif()
+else()
+  target_compile_options(${bun} PUBLIC
+    -Wno-nullability-completeness
+  )
 endif()
 
 # --- Linker options ---
diff --git a/src/bun.js/bindings/ExceptionOr.h b/src/bun.js/bindings/ExceptionOr.h
index 5241d45d5b..9581644f35 100644
--- a/src/bun.js/bindings/ExceptionOr.h
+++ b/src/bun.js/bindings/ExceptionOr.h
@@ -87,9 +87,6 @@ public:
 
 private:
     Expected<void, Exception> m_value;
-#if ASSERT_ENABLED
-    bool m_wasReleased { false };
-#endif
 };
 
 ExceptionOr<void> isolatedCopy(ExceptionOr<void>&&);
diff --git a/src/bun.js/bindings/root.h b/src/bun.js/bindings/root.h
index fd32e5868b..de68e2fec8 100644
--- a/src/bun.js/bindings/root.h
+++ b/src/bun.js/bindings/root.h
@@ -76,6 +76,8 @@
 #include <wtf/text/MakeString.h>
 #include <JavaScriptCore/JSCInlines.h>
 #include <JavaScriptCore/HandleSet.h>
+#include <wtf/Ref.h>
+#include <wtf/ThreadSafeRefCounted.h>
 
 #define ENABLE_WEB_CRYPTO 1
 #define USE_OPENSSL 1
diff --git a/src/bun.js/bindings/v8/V8FunctionTemplate.h b/src/bun.js/bindings/v8/V8FunctionTemplate.h
index 873b45a0da..4837406c80 100644
--- a/src/bun.js/bindings/v8/V8FunctionTemplate.h
+++ b/src/bun.js/bindings/v8/V8FunctionTemplate.h
@@ -34,8 +34,8 @@ enum class SideEffectType {
 // (v8-fast-api-calls.h is not in the headers distribution)
 class CFunction {
 private:
-    const void* address;
-    const void* type_info;
+    [[maybe_unused]] const void* address;
+    [[maybe_unused]] const void* type_info;
 };
 
 class FunctionTemplate : public Template {
diff --git a/src/bun.js/bindings/webcore/EventContext.h b/src/bun.js/bindings/webcore/EventContext.h
index 8fbd3c19fe..13f0469eb8 100644
--- a/src/bun.js/bindings/webcore/EventContext.h
+++ b/src/bun.js/bindings/webcore/EventContext.h
@@ -98,9 +98,9 @@ private:
     RefPtr<TouchList> m_targetTouches;
     RefPtr<TouchList> m_changedTouches;
 #endif
-    int m_closedShadowDepth { 0 };
-    bool m_currentTargetIsInShadowTree { false };
-    bool m_contextNodeIsFormElement { false };
+    [[maybe_unused]] int m_closedShadowDepth { 0 };
+    [[maybe_unused]] bool m_currentTargetIsInShadowTree { false };
+    [[maybe_unused]] bool m_contextNodeIsFormElement { false };
     Type m_type { Type::Normal };
 };
 
diff --git a/src/bun.js/bindings/webcore/EventNames.h b/src/bun.js/bindings/webcore/EventNames.h
index bc6f291f38..600be7daf6 100644
--- a/src/bun.js/bindings/webcore/EventNames.h
+++ b/src/bun.js/bindings/webcore/EventNames.h
@@ -81,7 +81,7 @@ private:
     EventNames(); // Private to prevent accidental call to EventNames() instead of eventNames().
     // friend class ThreadGlobalData; // Allow ThreadGlobalData to create the per-thread EventNames object.
 
-    int dummy; // Needed to make initialization macro work.
+    [[maybe_unused]] int dummy; // Needed to make initialization macro work.
 };
 
 const EventNames& eventNames();
diff --git a/src/bun.js/bindings/webcore/Worker.h b/src/bun.js/bindings/webcore/Worker.h
index 8d3044f212..1c1c992472 100644
--- a/src/bun.js/bindings/webcore/Worker.h
+++ b/src/bun.js/bindings/webcore/Worker.h
@@ -137,7 +137,6 @@ private:
     Deque<RefPtr<Event>> m_pendingEvents;
     Lock m_pendingTasksMutex;
     Deque<Function<void(ScriptExecutionContext&)>> m_pendingTasks;
-    bool m_didStartWorkerGlobalScope { false };
     // Tracks OnlineFlag and ClosingFlag
     std::atomic<uint8_t> m_onlineClosingFlags { 0 };
     // Tracks TerminateRequestedFlag and TerminatedFlag
diff --git a/src/codegen/bundle-functions.ts b/src/codegen/bundle-functions.ts
index d6a0e951da..003b0e2276 100644
--- a/src/codegen/bundle-functions.ts
+++ b/src/codegen/bundle-functions.ts
@@ -595,7 +595,7 @@ JSBuiltinInternalFunctions::JSBuiltinInternalFunctions(JSC::VM& vm) : m_vm(vm)
         void exportNames();
 
     private:
-        JSC::VM& m_vm;
+        [[maybe_unused]] JSC::VM& m_vm;
 
         WEBCORE_FOREACH_${basename.toUpperCase()}_BUILTIN_FUNCTION_NAME(DECLARE_BUILTIN_NAMES)
 
@@ -638,7 +638,7 @@ JSBuiltinInternalFunctions::JSBuiltinInternalFunctions(JSC::VM& vm) : m_vm(vm)
         template<typename Visitor> void visit(Visitor&);
 
     public:
-        JSC::VM& m_vm;
+        [[maybe_unused]] JSC::VM& m_vm;
 
     #define DECLARE_BUILTIN_SOURCE_MEMBERS(functionName) \\
         JSC::WriteBarrier<JSC::JSFunction> m_##functionName##Function;
@@ -682,7 +682,7 @@ JSBuiltinInternalFunctions::JSBuiltinInternalFunctions(JSC::VM& vm) : m_vm(vm)
 
   bundledHeader += `
     private:
-        JSC::VM& m_vm;
+        [[maybe_unused]] JSC::VM& m_vm;
     `;
 
   for (const { basename } of files) {
@@ -708,7 +708,7 @@ JSBuiltinInternalFunctions::JSBuiltinInternalFunctions(JSC::VM& vm) : m_vm(vm)
 
   bundledHeader += `
     private:
-        JSC::VM& m_vm;
+        [[maybe_unused]] JSC::VM& m_vm;
     `;
 
   for (const { basename, internal } of files) {