1 files changed, 2 insertions, 1 deletions
diff --git a/third_party/nix/src/libutil/args.hh b/third_party/nix/src/libutil/args.hh
index 3057f3d2ab..57720439bd 100644
--- a/third_party/nix/src/libutil/args.hh
+++ b/third_party/nix/src/libutil/args.hh
@@ -181,9 +181,10 @@ class Args {
         .arity(1)
         .handler([=](std::vector<std::string> ss) {
           I n;
-          if (!absl::SimpleAtoi(ss[0], &n))
+          if (!absl::SimpleAtoi(ss[0], &n)) {
             throw UsageError("flag '--%s' requires a integer argument",
                              longName);
+          }
           fun(n);
         });
   }