1 files changed, 4 insertions, 2 deletions
diff --git a/src/libstore/globals.cc b/src/libstore/globals.cc
index 683fa5196..4a5971c3f 100644
--- a/src/libstore/globals.cc
+++ b/src/libstore/globals.cc
@@ -9,6 +9,8 @@
 #include <dlfcn.h>
 #include <sys/utsname.h>
 
+#include <nlohmann/json.hpp>
+
 
 namespace nix {
 
@@ -160,9 +162,9 @@ template<> std::string BaseSetting<SandboxMode>::to_string() const
     else abort();
 }
 
-template<> void BaseSetting<SandboxMode>::toJSON(JSONPlaceholder & out)
+template<> nlohmann::json BaseSetting<SandboxMode>::toJSON()
 {
-    AbstractSetting::toJSON(out);
+    return AbstractSetting::toJSON();
 }
 
 template<> void BaseSetting<SandboxMode>::convertToArg(Args & args, const std::string & category)