diff -up libebml-1.4.2/src/EbmlString.cpp.gcc11 libebml-1.4.2/src/EbmlString.cpp
--- libebml-1.4.2/src/EbmlString.cpp.gcc11	2021-02-18 12:42:59.000000000 +0100
+++ libebml-1.4.2/src/EbmlString.cpp	2021-03-01 11:42:02.122854703 +0100
@@ -34,6 +34,7 @@
   \author Steve Lhomme     <robux4 @ users.sf.net>
 */
 #include <cassert>
+#include <limits>
 
 #include "ebml/EbmlString.h"
 
diff -up libebml-1.4.2/src/EbmlUnicodeString.cpp.gcc11 libebml-1.4.2/src/EbmlUnicodeString.cpp
--- libebml-1.4.2/src/EbmlUnicodeString.cpp.gcc11	2021-03-01 11:42:02.121854696 +0100
+++ libebml-1.4.2/src/EbmlUnicodeString.cpp	2021-03-01 11:42:21.772995170 +0100
@@ -36,6 +36,7 @@
 */
 
 #include <cassert>
+#include <limits>
 
 #include "ebml/EbmlUnicodeString.h"