diff --git a/lib/std/heap/ArenaAllocator.zig b/lib/std/heap/ArenaAllocator.zig
index 9f352ace33d24be624e16023f03ec995ce3a4e98..9711637cf63d9b0219a944b5cefe58ac58796ee0 100644
--- a/lib/std/heap/ArenaAllocator.zig
+++ b/lib/std/heap/ArenaAllocator.zig
@@ -735,7 +735,8 @@ fn fuzzMultiThreaded(fuzz_init: FuzzContext.Init, smith: *std.testing.Smith) any
                 n_allocs += 1;
                 ctx.allocs[alloc_index].common.len = .free;
                 group.concurrent(io, FuzzContext.doOneAlloc, .{
-                    &ctx, nextLen(smith),
+                    &ctx,
+                    nextLen(smith),
                     smith.valueRangeAtMost(
                         Alignment,
                         .@"1",