diff --git a/src-self-hosted/main.zig b/src-self-hosted/main.zig
index 51cc0014a1..8dc1d8ce3b 100644
--- a/src-self-hosted/main.zig
+++ b/src-self-hosted/main.zig
@@ -710,6 +710,7 @@ fn cmdFmt(allocator: &Allocator, args: []const []const u8) !void {
         defer baf.destroy();
 
         try std.zig.render(allocator, baf.stream(), &tree);
+        try baf.finish();
     }
 }