1 files changed, 1 insertions, 1 deletions
diff --git a/src/nix/doctor.cc b/src/nix/doctor.cc
index ea87e3d87..7da4549a1 100644
--- a/src/nix/doctor.cc
+++ b/src/nix/doctor.cc
@@ -18,7 +18,7 @@ std::string formatProtocol(unsigned int proto)
     if (proto) {
         auto major = GET_PROTOCOL_MAJOR(proto) >> 8;
         auto minor = GET_PROTOCOL_MINOR(proto);
-        return (format("%1%.%2%") % major % minor).str();
+        return fmt("%1%.%2%", major, minor);
     }
     return "unknown";
 }