diff --git a/python/mrc/_pymrc/src/segment.cpp b/python/mrc/_pymrc/src/segment.cpp
index b55deb128..35ae0129f 100644
--- a/python/mrc/_pymrc/src/segment.cpp
+++ b/python/mrc/_pymrc/src/segment.cpp
@@ -33,6 +33,7 @@
 #include "mrc/segment/object.hpp"
 
 #include <glog/logging.h>
+#include <nlohmann/json.hpp>
 #include <pybind11/cast.h>
 #include <pybind11/gil.h>
 #include <pybind11/pytypes.h>