diff --git a/stream/gear/src/Property.cpp b/stream/gear/src/Property.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..eeb186ab169844ae30e5608290b6e59a773d0c21
--- /dev/null
+++ b/stream/gear/src/Property.cpp
@@ -0,0 +1,12 @@
+#include <Property.cuh>
+
+void from_json(const nlohmann::json& j, dim3& d)
+{
+  const auto ar = j.get<std::array<unsigned, 3>>();
+  d = {ar[0], ar[1], ar[2]};
+}
+
+void to_json(nlohmann::json& j, const dim3& d)
+{
+  j = nlohmann::json{ d.x, d.y, d.z };
+}