Steve Alan Duncan appeals from his conviction by a United States District Judge sitting without jury for possession of 388 pounds of marijuana with intent to distribute, 21 U.S.C. § 841(a)(1). We affirm the conviction.

Duncan was stopped by border patrol agents at a permanent checkpoint seven miles south of Falfurrias, Texas. When *904 Duncan opened his car window several inches to answer an agent’s questions, the agent detected the odor of marijuana. After informing Duncan of his rights the agent asked Duncan to open the trunk of his car; the marijuana was inside the trunk.

On appeal Duncan argues that to allow odor alone to provide probable cause “is to leave all motorists at the mercy of an officer’s whimsical olfactory sense.” This argument is without merit. Detection of the distinctive odor of marijuana is sufficient to establish probable cause, United States v. Diaz, 5 Cir., 1976, 541 F.2d 1165, 1166.

AFFIRMED.