diff --git a/ml_date.cpp b/ml_date.cpp
index 0e6373c..ee0304f 100644
--- a/ml_date.cpp
+++ b/ml_date.cpp
@@ -1,6 +1,7 @@
 
 #include "ml_date.h"
 #include <cstring>
+#include <stdexcept>
 
 long now() {	// get-universal-time
 	time_t t = std::time(nullptr);