diff --git a/lib/std/Build/Step.zig b/lib/std/Build/Step.zig
index c3392c4301..3002db628f 100644
--- a/lib/std/Build/Step.zig
+++ b/lib/std/Build/Step.zig
@@ -271,7 +271,7 @@ pub fn make(s: *Step, options: MakeOptions) error{ MakeFailed, MakeSkipped }!voi
     }
 
     if (s.max_rss != 0 and s.result_peak_rss > s.max_rss) {
-        const msg = std.fmt.allocPrint(arena, "memory usage peaked at {d} bytes, exceeding the declared upper bound of {d}", .{
+        const msg = std.fmt.allocPrint(arena, "memory usage peaked at {0B:.2} ({0d} bytes), exceeding the declared upper bound of {1B:.2} ({1d} bytes)", .{
             s.result_peak_rss, s.max_rss,
         }) catch @panic("OOM");
         s.result_error_msgs.append(arena, msg) catch @panic("OOM");