Talk about man bites dog. I actually have something favorable to say about that beleaguered stock-market watchdog, the Securities and Exchange Commission. Well, almost favorable.

The SEC’s enforcement division, which has been rightly criticized for failing to catch Bernard L. Madoff and a host of other bad actors in the financial crisis, announced a reorganization the other day, its first in nearly four decades. It is, overall, a good thing. But it could be made a lot better.

From now on, the SEC’s enforcers will be divided among five divisions, each focusing on a particular area of concern: asset management, market abuse, structured and new products, foreign corrupt practices, and municipal securities and public pensions. This may seem like bureaucratic deck-shuffling to some, but it’s a great idea. It means that the SEC is placing special emphasis on carefully selected areas of concern so that it can detect emerging problems and react quickly.

It is particularly gratifying to see the unit focusing on “structured and new products”—such as the mortgage-backed securities that proved so troublesome during the housing boom and bust. Hey, they’re only 15 years late doing this, but better late than never. Ditto for the asset-management unit, which will encompass hedge funds, long an area of regulatory neglect.

The SEC gets an A for effort for doing this, but I was disappointed by the units that the SEC did not create. Yes, those five areas are important. Heck, it’s hard to find five areas in the SEC’s orbit that would not be important. But the SEC erred by failing to include two units: one focusing on misconduct by public companies and another focusing on small companies and entrepreneurs.

The neglect of corporate misconduct is surprising. Here’s the SEC press release announcing the reorganization. Read it and ask yourself this question: Where would Enron fit into these categories? “Market abuse” would seem closest, but the SEC announcement gives it a very specific focus: “investigations involving large-scale market abuses and complex manipulation schemes by institutional traders, market professionals, and others.” Crooked execs cooking the books, with the consent of a somnolent board of directors, don’t fit into that template. The same goes for any of the corporate scandals that have arisen over the past decade.