diff --git a/reactos/dll/win32/gdi32/gdi32.def b/reactos/dll/win32/gdi32/gdi32.def
index 2f18b8c7015..c4581a52ec9 100644
--- a/reactos/dll/win32/gdi32/gdi32.def
+++ b/reactos/dll/win32/gdi32/gdi32.def
@@ -622,3 +622,4 @@ bInitSystemAndFontsDirectoriesW@8
 bMakePathNameW@16
 cGetTTFFromFOT@28
 gdiPlaySpoolStream@24
+GdiGetBitmapBitsSize@4
\ No newline at end of file
diff --git a/reactos/dll/win32/gdi32/include/gdi32p.h b/reactos/dll/win32/gdi32/include/gdi32p.h
index 3ae11549c7c..2ae1f53deda 100644
--- a/reactos/dll/win32/gdi32/include/gdi32p.h
+++ b/reactos/dll/win32/gdi32/include/gdi32p.h
@@ -233,5 +233,8 @@ GdiSetLastError( DWORD dwErrCode );
 DWORD WINAPI GdiGetCodePage(HDC);
 UINT FASTCALL DIB_BitmapBitsSize( PBITMAPINFO );
 
-/* EOF */
+int
+WINAPI
+GdiGetBitmapBitsSize(BITMAPINFO *lpbmi);
 
+/* EOF */