diff --git a/mp4/mp4tagfield.h b/mp4/mp4tagfield.h
index 3500e51..f99b70c 100644
--- a/mp4/mp4tagfield.h
+++ b/mp4/mp4tagfield.h
@@ -7,6 +7,7 @@
 #include <c++utilities/io/binarywriter.h>
 
 #include <vector>
+#include <sstream>
 
 namespace Media
 {