diff --git a/src/util/json/value.cpp b/src/util/json/value.cpp
index d831329..0cd56b8 100644
--- a/src/util/json/value.cpp
+++ b/src/util/json/value.cpp
@@ -12,6 +12,7 @@
 #include <string>
 #include <utility> // move, swap
 
+#include "util/format/format.h"
 #include "util/json/array.h"
 #include "util/json/job.h"
 #include "util/json/object.h"
@@ -331,4 +332,9 @@ std::ostream& operator<<(std::ostream& output, const Value& value)
 	return output << value.dump(4);
 }
 
+void format(FormatBuilder& builder, const Value& value)
+{
+	builder.putString(value.dump(4));
+}
+
 } // namespace Json
diff --git a/src/util/json/value.h b/src/util/json/value.h
index 784ef54..cf75c2f 100644
--- a/src/util/json/value.h
+++ b/src/util/json/value.h
@@ -14,6 +14,7 @@
 #include <string>
 #include <utility> // forward
 
+#include "util/format/format.h"
 #include "util/json/fromjson.h"
 #include "util/json/tojson.h"
 
@@ -134,6 +135,8 @@ private:
 std::istream& operator>>(std::istream& input, Value& value);
 std::ostream& operator<<(std::ostream& output, const Value& value);
 
+void format(FormatBuilder& builder, const Value& value);
+
 } // namespace Json
 
 /**