diff --git a/dlls/wined3d/device.c b/dlls/wined3d/device.c
index 7fd6eee4ccf..a585d259829 100644
--- a/dlls/wined3d/device.c
+++ b/dlls/wined3d/device.c
@@ -3574,7 +3574,7 @@ static HRESULT process_vertices_strided(const struct wined3d_device *device, DWO
 /* Do not call while under the GL lock. */
 HRESULT CDECL wined3d_device_process_vertices(struct wined3d_device *device,
         UINT src_start_idx, UINT dst_idx, UINT vertex_count, struct wined3d_buffer *dst_buffer,
-        struct wined3d_vertex_declaration *declaration, DWORD flags, DWORD dst_fvf)
+        const struct wined3d_vertex_declaration *declaration, DWORD flags, DWORD dst_fvf)
 {
     struct wined3d_state *state = &device->stateBlock->state;
     BOOL vbo = FALSE, streamWasUP = state->user_stream;
diff --git a/include/wine/wined3d.h b/include/wine/wined3d.h
index 85f47b4c852..fbd51037562 100644
--- a/include/wine/wined3d.h
+++ b/include/wine/wined3d.h
@@ -2282,7 +2282,7 @@ HRESULT __cdecl wined3d_device_present(struct wined3d_device *device, const RECT
         const RECT *dst_rect, HWND dst_window_override, const RGNDATA *dirty_region);
 HRESULT __cdecl wined3d_device_process_vertices(struct wined3d_device *device,
         UINT src_start_idx, UINT dst_idx, UINT vertex_count, struct wined3d_buffer *dst_buffer,
-        struct wined3d_vertex_declaration *declaration, DWORD flags, DWORD dst_fvf);
+        const struct wined3d_vertex_declaration *declaration, DWORD flags, DWORD dst_fvf);
 void __cdecl wined3d_device_release_focus_window(struct wined3d_device *device);
 HRESULT __cdecl wined3d_device_reset(struct wined3d_device *device,
         WINED3DPRESENT_PARAMETERS *present_parameters, wined3d_device_reset_cb callback);