diff --git a/subprojects/gst-plugins-bad/gst-libs/gst/d3d11/gstd3d11converter.cpp b/subprojects/gst-plugins-bad/gst-libs/gst/d3d11/gstd3d11converter.cpp
index 603f9f521d..8eaebe39b5 100644
--- a/subprojects/gst-plugins-bad/gst-libs/gst/d3d11/gstd3d11converter.cpp
+++ b/subprojects/gst-plugins-bad/gst-libs/gst/d3d11/gstd3d11converter.cpp
@@ -2367,7 +2367,7 @@ gst_d3d11_converter_convert_internal (GstD3D11Converter * self,
     }
 
     alpha_buffer = (PSAlphaFactor *) map.pData;
-    memcpy (alpha_buffer, &priv->alpha_data, sizeof (PSConstBuffer));
+    memcpy (alpha_buffer, &priv->alpha_data, sizeof (PSAlphaFactor));
 
     context->Unmap (priv->alpha_buffer.Get (), 0);
   }