MEMORANDUM **

Mark Steven Erckert appeals from his jury-trial conviction for conspiracy to man*46ufacture, distribute, and possess with intent to distribute methamphetamine, in violation of 21 U.S.C. §§ 841(a)(1) and 846. We have jurisdiction pursuant to 28 U.S.C. § 1291, and we affirm.

Erckert contends that the district court committed plain error, warranting reversal of his conviction, because the district court did not instruct the jury that a buyer-seller relationship is insufficient to establish a conspiracy. However, given the strength of the government’s case, Erc-kert’s failure to request a buyer-seller instruction, and the fact that Erckert “d[id] not rely on the theory of defense embodied in that instruction at trial,” the district court’s failure to offer the instruction sua sponte was not plain error. See United States v. Montgomery, 150 F.3d 988, 996 (9th Cir. 1998); United States v. Span, 970 F.2d 573, 578 (9th Cir. 1992).

AFFIRMED.