diff --git a/src/lib/format-obj.hpp b/src/lib/format-obj.hpp
index 9e5c803dc..e0772ea6f 100644
--- a/src/lib/format-obj.hpp
+++ b/src/lib/format-obj.hpp
@@ -46,7 +46,7 @@
 #ifndef LIB_FORMAT_OBJ_H
 #define LIB_FORMAT_OBJ_H
 
-#include <string>
+#include "lib/symbol.hpp"
 #include "lib/meta/trait.hpp"
 
 #include <boost/lexical_cast.hpp>
diff --git a/src/lib/format-util.hpp b/src/lib/format-util.hpp
index 21105d7ca..5af1f0efa 100644
--- a/src/lib/format-util.hpp
+++ b/src/lib/format-util.hpp
@@ -38,7 +38,6 @@
 #ifndef LIB_FORMAT_UTIL_H
 #define LIB_FORMAT_UTIL_H
 
-#include "lib/hash-standard.hpp"
 #include "lib/meta/trait.hpp"
 #include "lib/format-obj.hpp"
 #include "lib/itertools.hpp"