Add header guard.

diff --git a/src/lib/audio_merger.h b/src/lib/audio_merger.h
index dbc0c869103b44d69b5bbe301e9134bcdb752f02..e685a28bf0287c809ce8edaf243be8388925b63c 100644 (file)
--- a/src/lib/audio_merger.h
+++ b/src/lib/audio_merger.h
@@ -17,6 +17,9 @@
 
 */
 
+#ifndef DCPOMATIC_AUDIO_MERGER_H
+#define DCPOMATIC_AUDIO_MERGER_H
+
 /** @file  src/audio_merger.h
  *  @brief AudioMerger class.
  */
@@ -81,3 +84,5 @@ private:
        std::list<Buffer> _buffers;
        int _frame_rate;
 };
+
+#endif