const build fix.

diff --git a/src/dcp_reader.cc b/src/dcp_reader.cc
index 5f57746eb38f5ec409188d3a30b70168be5738f4..6c35c05dc64ed5d057c387bff5fab1360885a863 100644 (file)
--- a/src/dcp_reader.cc
+++ b/src/dcp_reader.cc
@@ -73,7 +73,7 @@ DCPReader::DCPReader (boost::filesystem::path file)
        for (auto i: sc->subtitles()) {
 
                /* We don't deal with image subs */
-               auto is = dynamic_pointer_cast<dcp::SubtitleString>(i);
+               auto is = dynamic_pointer_cast<const dcp::SubtitleString>(i);
                if (!is) {
                        continue;
                }