--- a/src/sbml/html2md/html2md.h
+++ b/src/sbml/html2md/html2md.h
@@ -8,6 +8,8 @@
 #include <string>
 #include <unordered_map>
 
+#include <stdint.h>
+
 /*!
  * \brief html2md namespace
  *