1 files changed, 5 insertions, 0 deletions
diff --git a/src/frame.h b/src/frame.h
index 54b74e55..f20a1bb3 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -31,6 +31,9 @@
     files in the program, then also delete it here.
 */
 
+#ifndef LIBDCP_FRAME_H
+#define LIBDCP_FRAME_H
+
 #include "decryption_context.h"
 #include "exceptions.h"
 #include <asdcp/KM_fileio.h>
@@ -73,3 +76,5 @@ private:
 };
 
 }
+
+#endif