diff --git a/inc/hook.h b/inc/hook.h
index cd1dab8..f6d175f 100644
--- a/inc/hook.h
+++ b/inc/hook.h
@@ -58,6 +58,9 @@ typedef BOOL(WINAPI* PEEKMESSAGEAPROC)(LPMSG, HWND, UINT, UINT, UINT);
 typedef BOOL(WINAPI* GETMESSAGEAPROC)(LPMSG, HWND, UINT, UINT);
 typedef BOOL(WINAPI* GETWINDOWPLACEMENTPROC)(HWND, WINDOWPLACEMENT*);
 typedef BOOL(WINAPI* ENUMDISPLAYSETTINGSAPROC)(LPCSTR, DWORD, DEVMODEA*);
+
+typedef BOOL(WINAPI* VALIDATERECTPROC)(HWND, const RECT*);
+typedef BOOL(WINAPI* INVALIDATERECTPROC)(HWND, const RECT*, BOOL);
 typedef SHORT(WINAPI* GETKEYSTATEPROC)(int);
 typedef SHORT(WINAPI* GETASYNCKEYSTATEPROC)(int);
 
@@ -109,6 +112,8 @@ extern PEEKMESSAGEAPROC real_PeekMessageA;
 extern GETMESSAGEAPROC real_GetMessageA;
 extern GETWINDOWPLACEMENTPROC real_GetWindowPlacement;
 extern ENUMDISPLAYSETTINGSAPROC real_EnumDisplaySettingsA;
+extern VALIDATERECTPROC real_ValidateRect;
+extern INVALIDATERECTPROC real_InvalidateRect;
 extern GETKEYSTATEPROC real_GetKeyState;
 extern GETASYNCKEYSTATEPROC real_GetAsyncKeyState;
 extern GETDEVICECAPSPROC real_GetDeviceCaps;
diff --git a/inc/winapi_hooks.h b/inc/winapi_hooks.h
index 6e2965d..4ec75c9 100644
--- a/inc/winapi_hooks.h
+++ b/inc/winapi_hooks.h
@@ -34,6 +34,8 @@ BOOL WINAPI fake_PeekMessageA(LPMSG lpMsg, HWND hWnd, UINT wMsgFilterMin, UINT w
 BOOL WINAPI fake_GetMessageA(LPMSG lpMsg, HWND hWnd, UINT wMsgFilterMin, UINT wMsgFilterMax);
 BOOL WINAPI fake_GetWindowPlacement(HWND hWnd, WINDOWPLACEMENT* lpwndpl);
 BOOL WINAPI fake_EnumDisplaySettingsA(LPCSTR lpszDeviceName, DWORD iModeNum, DEVMODEA* lpDevMode);
+BOOL WINAPI fake_ValidateRect(HWND hWnd, const RECT* lpRect);
+BOOL WINAPI fake_InvalidateRect(HWND hWnd, const RECT* lpRect, BOOL bErase);
 SHORT WINAPI fake_GetKeyState(int nVirtKey);
 SHORT WINAPI fake_GetAsyncKeyState(int vKey);
 int WINAPI fake_GetDeviceCaps(HDC hdc, int index);
diff --git a/src/hook.c b/src/hook.c
index 416125c..bab3648 100644
--- a/src/hook.c
+++ b/src/hook.c
@@ -51,6 +51,8 @@ PEEKMESSAGEAPROC real_PeekMessageA = PeekMessageA;
 GETMESSAGEAPROC real_GetMessageA = GetMessageA;
 GETWINDOWPLACEMENTPROC real_GetWindowPlacement = GetWindowPlacement;
 ENUMDISPLAYSETTINGSAPROC real_EnumDisplaySettingsA = EnumDisplaySettingsA;
+VALIDATERECTPROC real_ValidateRect = ValidateRect;
+INVALIDATERECTPROC real_InvalidateRect = InvalidateRect;
 GETKEYSTATEPROC real_GetKeyState = GetKeyState;
 GETASYNCKEYSTATEPROC real_GetAsyncKeyState = GetAsyncKeyState;
 GETDEVICECAPSPROC real_GetDeviceCaps = GetDeviceCaps;
@@ -100,6 +102,8 @@ HOOKLIST g_hook_hooklist[] =
             //{ "GetMessageA", (PROC)fake_GetMessageA, (PROC*)&real_GetMessageA, 0 },
             { "GetWindowPlacement", (PROC)fake_GetWindowPlacement, (PROC*)&real_GetWindowPlacement, 0 },
             { "EnumDisplaySettingsA", (PROC)fake_EnumDisplaySettingsA, (PROC*)&real_EnumDisplaySettingsA, 0 },
+            { "ValidateRect", (PROC)fake_ValidateRect, (PROC*)&real_ValidateRect, 0 },
+            { "InvalidateRect", (PROC)fake_InvalidateRect, (PROC*)&real_InvalidateRect, 0 },
             { "GetKeyState", (PROC)fake_GetKeyState, (PROC*)&real_GetKeyState, 0 },
             { "GetAsyncKeyState", (PROC)fake_GetAsyncKeyState, (PROC*)&real_GetAsyncKeyState, 0 },
             { "SetForegroundWindow", (PROC)fake_SetForegroundWindow, (PROC*)&real_SetForegroundWindow, 0 },
diff --git a/src/winapi_hooks.c b/src/winapi_hooks.c
index b856f0e..f6bd9e8 100644
--- a/src/winapi_hooks.c
+++ b/src/winapi_hooks.c
@@ -822,6 +822,46 @@ BOOL WINAPI fake_EnumDisplaySettingsA(LPCSTR lpszDeviceName, DWORD iModeNum, DEV
     return result;
 }
 
+BOOL WINAPI fake_ValidateRect(HWND hWnd, const RECT* lpRect)
+{
+    if (!g_ddraw.ref || !g_ddraw.width || !g_ddraw.hwnd || hWnd != g_ddraw.hwnd || !lpRect)
+        return real_ValidateRect(hWnd, lpRect);
+
+    RECT dst_rc;
+
+    dst_rc.left = (LONG)(roundf(lpRect->left * g_ddraw.render.scale_w));
+    dst_rc.top = (LONG)(roundf(lpRect->top * g_ddraw.render.scale_h));
+    dst_rc.bottom = (LONG)(roundf(lpRect->bottom * g_ddraw.render.scale_h));
+    dst_rc.right = (LONG)(roundf(lpRect->right * g_ddraw.render.scale_w));
+
+    OffsetRect(
+        &dst_rc,
+        g_ddraw.render.viewport.x,
+        g_ddraw.render.viewport.y);
+
+    return real_ValidateRect(hWnd, lpRect);
+}
+
+BOOL WINAPI fake_InvalidateRect(HWND hWnd, const RECT* lpRect, BOOL bErase)
+{
+    if (!g_ddraw.ref || !g_ddraw.width || !g_ddraw.hwnd || hWnd != g_ddraw.hwnd || !lpRect)
+        return real_InvalidateRect(hWnd, lpRect, bErase);
+
+    RECT dst_rc;
+
+    dst_rc.left = (LONG)(roundf(lpRect->left * g_ddraw.render.scale_w));
+    dst_rc.top = (LONG)(roundf(lpRect->top * g_ddraw.render.scale_h));
+    dst_rc.bottom = (LONG)(roundf(lpRect->bottom * g_ddraw.render.scale_h));
+    dst_rc.right = (LONG)(roundf(lpRect->right * g_ddraw.render.scale_w));
+
+    OffsetRect(
+        &dst_rc,
+        g_ddraw.render.viewport.x,
+        g_ddraw.render.viewport.y);
+
+    return real_InvalidateRect(hWnd, &dst_rc, bErase);
+}
+
 SHORT WINAPI fake_GetKeyState(int nVirtKey)
 {
     if (g_config.windowed && g_ddraw.ref && g_ddraw.hwnd && !util_in_foreground())