diff --git a/src/extension/extension.cpp b/src/extension/extension.cpp
index f8ed2d6f283..ea57b31f28b 100644
--- a/src/extension/extension.cpp
+++ b/src/extension/extension.cpp
@@ -11,16 +11,6 @@
 #include "main/database.h"
 #include "transaction/transaction.h"
 
-#ifdef _WIN32
-
-#include "windows.h"
-#define RTLD_NOW 0
-#define RTLD_LOCAL 0
-
-#else
-#include <dlfcn.h>
-#endif
-
 namespace kuzu {
 namespace extension {
 
diff --git a/src/include/extension/extension.h b/src/include/extension/extension.h
index d11fcd741d6..0729a532887 100644
--- a/src/include/extension/extension.h
+++ b/src/include/extension/extension.h
@@ -6,6 +6,17 @@
 #include "common/api.h"
 #include "function/function.h"
 #include "main/db_config.h"
+#include "common/exception/io.h"
+
+#ifdef _WIN32
+
+#include "windows.h"
+#define RTLD_NOW 0
+#define RTLD_LOCAL 0
+
+#else
+#include <dlfcn.h>
+#endif
 
 #define ADD_FUNC(FUNC_STRUCT)                                                                      \
     kuzu::extension::ExtensionUtils::registerFunctionSet(db, std::string(FUNC_STRUCT::name),       \
@@ -125,5 +136,33 @@ struct ExtensionOptions {
     main::ExtensionOption* getExtensionOption(std::string name);
 };
 
+#ifdef _WIN32
+std::wstring utf8ToUnicode(const char* input) {
+    uint32_t result;
+
+    result = MultiByteToWideChar(CP_UTF8, 0, input, -1, nullptr, 0);
+    if (result == 0) {
+        throw common::IOException("Failure in MultiByteToWideChar");
+    }
+    auto buffer = std::make_unique<wchar_t[]>(result);
+    result = MultiByteToWideChar(CP_UTF8, 0, input, -1, buffer.get(), result);
+    if (result == 0) {
+        throw common::IOException("Failure in MultiByteToWideChar");
+    }
+    return std::wstring(buffer.get(), result);
+}
+
+void* dlopen(const char* file, int /*mode*/) {
+    KU_ASSERT(file);
+    auto fpath = utf8ToUnicode(file);
+    return (void*)LoadLibraryW(fpath.c_str());
+}
+
+void* dlsym(void* handle, const char* name) {
+    KU_ASSERT(handle);
+    return (void*)GetProcAddress((HINSTANCE)handle, name);
+}
+#endif
+
 } // namespace extension
 } // namespace kuzu
diff --git a/src/processor/operator/simple/load_extension.cpp b/src/processor/operator/simple/load_extension.cpp
index b5e66a3dccd..420069996c2 100644
--- a/src/processor/operator/simple/load_extension.cpp
+++ b/src/processor/operator/simple/load_extension.cpp
@@ -15,34 +15,6 @@ std::string LoadExtensionPrintInfo::toString() const {
     return "Load " + extensionName;
 }
 
-#ifdef _WIN32
-std::wstring utf8ToUnicode(const char* input) {
-    uint32_t result;
-
-    result = MultiByteToWideChar(CP_UTF8, 0, input, -1, nullptr, 0);
-    if (result == 0) {
-        throw IOException("Failure in MultiByteToWideChar");
-    }
-    auto buffer = std::make_unique<wchar_t[]>(result);
-    result = MultiByteToWideChar(CP_UTF8, 0, input, -1, buffer.get(), result);
-    if (result == 0) {
-        throw IOException("Failure in MultiByteToWideChar");
-    }
-    return std::wstring(buffer.get(), result);
-}
-
-void* dlopen(const char* file, int /*mode*/) {
-    KU_ASSERT(file);
-    auto fpath = utf8ToUnicode(file);
-    return (void*)LoadLibraryW(fpath.c_str());
-}
-
-void* dlsym(void* handle, const char* name) {
-    KU_ASSERT(handle);
-    return (void*)GetProcAddress((HINSTANCE)handle, name);
-}
-#endif
-
 static void executeExtensionLoader(main::ClientContext* context, const std::string& extensionName) {
     auto loaderPath = ExtensionUtils::getLocalPathForExtensionLoader(context, extensionName);
     if (context->getVFSUnsafe()->fileOrPathExists(loaderPath)) {