diff --git a/include/scmp/geom/Orientation.h b/include/scmp/geom/Orientation.h
index cfce891..3274438 100644
--- a/include/scmp/geom/Orientation.h
+++ b/include/scmp/geom/Orientation.h
@@ -4,6 +4,7 @@
  * of the Earth.
  */
 
+#include <cstdint>
 
 #ifndef SCMATH_GEOM_ORIENTATION_H
 #define SCMATH_GEOM_ORIENTATION_H