diff --git a/writer/HDF5Objects.cpp b/writer/HDF5Objects.cpp
index 9446e0d9..efecd72c 100644
--- a/writer/HDF5Objects.cpp
+++ b/writer/HDF5Objects.cpp
@@ -665,9 +665,9 @@ std::unique_ptr<HDF5DataSet> HDF5Object::SaveVector(const std::string &name, con
     HDF5DataSpace data_space({val.size()});
     auto dataset = std::make_unique<HDF5DataSet>(*this, name, data_type, data_space, dcpl);
 
-    char buffer[(len+1) * val.size()];
-    for (int i = 0; i < val.size(); i++) strncpy(buffer + i * (len+1), val[i].c_str(), len+1);
-    dataset->Write(data_type, buffer);
+    std::vector<char> buffer((len + 1) * val.size(), '\0');
+    for (int i = 0; i < val.size(); i++) strncpy(buffer.data() + i * (len+1), val[i].c_str(), len+1);
+    dataset->Write(data_type, buffer.data());
     return dataset;
 }