diff --git a/bee/platform/win/wtf8.h b/bee/platform/win/wtf8.h
index c023304b..2191b607 100644
--- a/bee/platform/win/wtf8.h
+++ b/bee/platform/win/wtf8.h
@@ -1,31 +1,8 @@
 #pragma once
 
-extern "C" {
-#include <bee/platform/win/wtf8_c.h>
-}
 #include <bee/utility/zstring_view.h>
 
 namespace bee::wtf8 {
-    inline std::wstring u2w(zstring_view str) noexcept {
-        if (str.empty()) {
-            return L"";
-        }
-        size_t wlen = wtf8_to_utf16_length(str.data(), str.size());
-        if (wlen == (size_t)-1) {
-            return L"";
-        }
-        std::wstring wresult(wlen, L'\0');
-        wtf8_to_utf16(str.data(), str.size(), wresult.data(), wlen);
-        return wresult;
-    }
-
-    inline std::string w2u(wzstring_view wstr) noexcept {
-        if (wstr.empty()) {
-            return "";
-        }
-        size_t len = wtf8_from_utf16_length(wstr.data(), wstr.size());
-        std::string result(len, '\0');
-        wtf8_from_utf16(wstr.data(), wstr.size(), result.data(), len);
-        return result;
-    }
+    std::wstring u2w(zstring_view str) noexcept;
+    std::string w2u(wzstring_view wstr) noexcept;
 }
diff --git a/bee/platform/win/wtf8_win.cpp b/bee/platform/win/wtf8_win.cpp
new file mode 100644
index 00000000..f5604660
--- /dev/null
+++ b/bee/platform/win/wtf8_win.cpp
@@ -0,0 +1,30 @@
+#include <bee/platform/win/wtf8.h>
+
+extern "C" {
+#include <bee/platform/win/wtf8_c.h>
+}
+
+namespace bee::wtf8 {
+    std::wstring u2w(zstring_view str) noexcept {
+        if (str.empty()) {
+            return L"";
+        }
+        size_t wlen = wtf8_to_utf16_length(str.data(), str.size());
+        if (wlen == (size_t)-1) {
+            return L"";
+        }
+        std::wstring wresult(wlen, L'\0');
+        wtf8_to_utf16(str.data(), str.size(), wresult.data(), wlen);
+        return wresult;
+    }
+
+    std::string w2u(wzstring_view wstr) noexcept {
+        if (wstr.empty()) {
+            return "";
+        }
+        size_t len = wtf8_from_utf16_length(wstr.data(), wstr.size());
+        std::string result(len, '\0');
+        wtf8_from_utf16(wstr.data(), wstr.size(), result.data(), len);
+        return result;
+    }
+}