diff --git a/lib/utils/mu-utils-format.hh b/lib/utils/mu-utils-format.hh
index 44c30b6d..3ee0bcdc 100644
--- a/lib/utils/mu-utils-format.hh
+++ b/lib/utils/mu-utils-format.hh
@@ -20,6 +20,9 @@
 #ifndef MU_UTILS_FORMAT_HH__
 #define MU_UTILS_FORMAT_HH__
 
+#include <string>
+#include <cstdarg>
+
 namespace Mu {
 
 /**