diff --git a/miniwin/miniwin/include/miniwin.h b/miniwin/miniwin/include/miniwin.h
index dd095581..b976a279 100644
--- a/miniwin/miniwin/include/miniwin.h
+++ b/miniwin/miniwin/include/miniwin.h
@@ -16,7 +16,7 @@
 #define CALLBACK
 #define FAR
 #define WINAPI
-#define HWND_NOTOPMOST (HWND) - 2
+#define HWND_NOTOPMOST -2
 #define RGB(r, g, b) ((r) | ((g) << 8) | ((b) << 16))
 #define S_OK ((HRESULT) 0)
 #define E_NOINTERFACE (0x80004002)
@@ -147,10 +147,7 @@ struct IUnknown {
 	int m_refCount;
 };
 
-inline BOOL SetWindowPos(HWND hWnd, HWND hWndInsertAfter, int X, int Y, int cx, int cy, UINT uFlags)
-{
-	return TRUE;
-}
+BOOL SetWindowPos(HWND hWnd, int hWndInsertAfter, int X, int Y, int cx, int cy, UINT uFlags);
 
 inline HDC WINAPI GetDC(HWND hWnd)
 {
diff --git a/miniwin/miniwin/src/miniwin.cpp b/miniwin/miniwin/src/miniwin.cpp
index 7eaad90e..9e26a590 100644
--- a/miniwin/miniwin/src/miniwin.cpp
+++ b/miniwin/miniwin/src/miniwin.cpp
@@ -24,6 +24,27 @@ HRESULT IUnknown::QueryInterface(const GUID& riid, void** ppvObject)
 	return E_NOINTERFACE;
 }
 
+BOOL SetWindowPos(HWND hWnd, int hWndInsertAfter, int X, int Y, int cx, int cy, UINT uFlags)
+{
+	if (!hWnd) {
+		return FALSE;
+	}
+
+	if (!(uFlags & SWP_NOACTIVATE)) {
+		SDL_RaiseWindow(hWnd);
+	}
+
+	if (!(uFlags & SWP_NOSIZE)) {
+		SDL_SetWindowSize(hWnd, cx, cy);
+	}
+
+	if (!(uFlags & SWP_NOMOVE)) {
+		SDL_SetWindowPosition(hWnd, X, Y);
+	}
+
+	return TRUE;
+}
+
 VOID WINAPI Sleep(DWORD dwMilliseconds)
 {
 	SDL_Delay(dwMilliseconds);