2 files changed, 6 insertions, 0 deletions
diff --git a/src/libutil/json.cc b/src/libutil/json.cc
index 619b1d631b9a..ecc3fdfe514e 100644
--- a/src/libutil/json.cc
+++ b/src/libutil/json.cc
@@ -29,6 +29,11 @@ void toJSON(std::ostream & str, const char * s)
     if (!s) str << "null"; else toJSON(str, s, s + strlen(s));
 }
 
+void toJSON(std::ostream & str, unsigned long long n)
+{
+    str << n;
+}
+
 void toJSON(std::ostream & str, unsigned long n)
 {
     str << n;
diff --git a/src/libutil/json.hh b/src/libutil/json.hh
index 852000a51b38..aec456845056 100644
--- a/src/libutil/json.hh
+++ b/src/libutil/json.hh
@@ -9,6 +9,7 @@ namespace nix {
 void toJSON(std::ostream & str, const char * start, const char * end);
 void toJSON(std::ostream & str, const std::string & s);
 void toJSON(std::ostream & str, const char * s);
+void toJSON(std::ostream & str, unsigned long long n);
 void toJSON(std::ostream & str, unsigned long n);
 void toJSON(std::ostream & str, long n);
 void toJSON(std::ostream & str, double f);