diff --git a/include/spark_dsg/serialization/json_conversions.h b/include/spark_dsg/serialization/json_conversions.h
index 226cc2a..bcb9324 100644
--- a/include/spark_dsg/serialization/json_conversions.h
+++ b/include/spark_dsg/serialization/json_conversions.h
@@ -112,7 +112,7 @@ struct adl_serializer<Eigen::Matrix<Scalar, Rows, Cols>> {
       throw std::runtime_error(ss.str());
     }
 
-    mat = Eigen::Matrix<Scalar, Rows, Cols>(rows, cols);
+    mat = Eigen::Matrix<Scalar, Rows, Cols>::Zero(rows, cols);
     for (size_t i = 0; i < vec->size(); ++i) {
       int r = i / cols;
       int c = i % cols;
diff --git a/include/spark_dsg/serialization/versioning.h b/include/spark_dsg/serialization/versioning.h
index 1ac6200..8b595ac 100644
--- a/include/spark_dsg/serialization/versioning.h
+++ b/include/spark_dsg/serialization/versioning.h
@@ -38,6 +38,7 @@
 #include <string>
 #include <unordered_map>
 #include <unordered_set>
+#include <cstdint>
 #include <vector>
 
 namespace spark_dsg::io {