diff --git a/dlls/windowscodecs/jpegformat.c b/dlls/windowscodecs/jpegformat.c
index eab50f02cd1..e9c722e5197 100644
--- a/dlls/windowscodecs/jpegformat.c
+++ b/dlls/windowscodecs/jpegformat.c
@@ -430,6 +430,8 @@ static HRESULT WINAPI JpegDecoder_GetThumbnail(IWICBitmapDecoder *iface,
 static HRESULT WINAPI JpegDecoder_GetFrameCount(IWICBitmapDecoder *iface,
     UINT *pCount)
 {
+    if (!pCount) return E_INVALIDARG;
+
     *pCount = 1;
     return S_OK;
 }