diff --git a/src/tpdate.hpp b/src/tpdate.hpp
index 4251781..c8974f1 100644
--- a/src/tpdate.hpp
+++ b/src/tpdate.hpp
@@ -20,6 +20,8 @@ namespace core {
 enum class JdSplitMethod { JD, J2000, MJD, DT };
 struct TwoPartJulianDate {
   double d0, d1;
+  explicit TwoPartJulianDate(double mjd0, double mjd1) noexcept
+      : d0(mjd0), d1(mjd1){};
 };
 
 /** Given an MJD, turn it to a JD and return it split in a convinient way