diff --git a/dlls/dmime/dmobject.c b/dlls/dmime/dmobject.c
index 2a0a540fdb7..0ef007530fd 100644
--- a/dlls/dmime/dmobject.c
+++ b/dlls/dmime/dmobject.c
@@ -349,7 +349,7 @@ HRESULT stream_get_chunk(IStream *stream, struct chunk_entry *chunk)
     return S_OK;
 }
 
-HRESULT stream_skip_chunk(IStream *stream, struct chunk_entry *chunk)
+HRESULT stream_skip_chunk(IStream *stream, const struct chunk_entry *chunk)
 {
     LARGE_INTEGER end;
 
diff --git a/dlls/dmime/dmobject.h b/dlls/dmime/dmobject.h
index fcbb89fd28b..a1729c83232 100644
--- a/dlls/dmime/dmobject.h
+++ b/dlls/dmime/dmobject.h
@@ -33,7 +33,7 @@ struct chunk_entry {
 
 HRESULT stream_get_chunk(IStream *stream, struct chunk_entry *chunk) DECLSPEC_HIDDEN;
 HRESULT stream_next_chunk(IStream *stream, struct chunk_entry *chunk) DECLSPEC_HIDDEN;
-HRESULT stream_skip_chunk(IStream *stream, struct chunk_entry *chunk) DECLSPEC_HIDDEN;
+HRESULT stream_skip_chunk(IStream *stream, const struct chunk_entry *chunk) DECLSPEC_HIDDEN;
 
 HRESULT stream_chunk_get_data(IStream *stream, const struct chunk_entry *chunk, void *data,
         ULONG size) DECLSPEC_HIDDEN;