diff --git a/ipv6/mrd6/patches/001-add_missing_include.patch b/ipv6/mrd6/patches/001-add_missing_include.patch
new file mode 100644
index 000000000..5501909b5
--- /dev/null
+++ b/ipv6/mrd6/patches/001-add_missing_include.patch
@@ -0,0 +1,10 @@
+--- a/include/mrd/support/ptree.h
++++ b/include/mrd/support/ptree.h
+@@ -35,6 +35,7 @@
+ #ifndef _Ptree_h_
+ #define _Ptree_h_
+ 
++#include <stddef.h>
+ #include <stdint.h>
+ #include <algorithm>
+ #include <mrd/log.h>