diff --git a/dlls/wined3d/arb_program_shader.c b/dlls/wined3d/arb_program_shader.c
index 797c2043680..15071820170 100644
--- a/dlls/wined3d/arb_program_shader.c
+++ b/dlls/wined3d/arb_program_shader.c
@@ -7715,6 +7715,7 @@ static HRESULT arbfp_blit_set(void *blit_priv, struct wined3d_context *context,
     }
     type.fixup = fixup;
     type.use_color_key = !!color_key;
+    type.padding = 0;
 
     entry = wine_rb_get(&priv->shaders, &type);
     if (entry)