diff --git a/include/internal/clara.h b/include/internal/clara.h
index 6493e01b..25544e7c 100644
--- a/include/internal/clara.h
+++ b/include/internal/clara.h
@@ -27,6 +27,7 @@
 #include <map>
 #include <algorithm>
 #include <stdexcept>
+#include <memory>
 
 // Use optional outer namespace
 #ifdef CLICHE_CLARA_OUTER_NAMESPACE