diff --git a/dlls/wined3d/device.c b/dlls/wined3d/device.c
index 792521a6225..ba688664893 100644
--- a/dlls/wined3d/device.c
+++ b/dlls/wined3d/device.c
@@ -1839,7 +1839,8 @@ HRESULT CDECL wined3d_device_set_stream_source_freq(struct wined3d_device *devic
     return WINED3D_OK;
 }
 
-HRESULT CDECL wined3d_device_get_stream_source_freq(struct wined3d_device *device, UINT stream_idx, UINT *divider)
+HRESULT CDECL wined3d_device_get_stream_source_freq(const struct wined3d_device *device,
+        UINT stream_idx, UINT *divider)
 {
     struct wined3d_stream_state *stream;
 
diff --git a/include/wine/wined3d.h b/include/wine/wined3d.h
index a523785996b..a0382606608 100644
--- a/include/wine/wined3d.h
+++ b/include/wine/wined3d.h
@@ -2248,7 +2248,8 @@ HRESULT __cdecl wined3d_device_get_scissor_rect(struct wined3d_device *device, R
 BOOL __cdecl wined3d_device_get_software_vertex_processing(struct wined3d_device *device);
 HRESULT __cdecl wined3d_device_get_stream_source(const struct wined3d_device *device,
         UINT stream_idx, struct wined3d_buffer **buffer, UINT *offset, UINT *stride);
-HRESULT __cdecl wined3d_device_get_stream_source_freq(struct wined3d_device *device, UINT stream_idx, UINT *divider);
+HRESULT __cdecl wined3d_device_get_stream_source_freq(const struct wined3d_device *device,
+        UINT stream_idx, UINT *divider);
 HRESULT __cdecl wined3d_device_get_surface_from_dc(struct wined3d_device *device,
         HDC dc, struct wined3d_surface **surface);
 HRESULT __cdecl wined3d_device_get_swapchain(const struct wined3d_device *device,