On March 16, 1976, appellant pleaded guilty to charges of robbery,1 theft2 and recklessly endangering another person.3 *401Following sentencing, appellant filed a direct appeal to this court challenging the plea as not knowingly, intelligently or voluntarily entered.
Appellant entered his plea several months after this court’s decision in Commonwealth v. Roberts, 237 Pa.Super. 336, 352 A.2d 140 (1975). Appellant failed, however, to comport with the Roberts requirement that prior to attacking a guilty plea on appeal, one must petition the lower court for permission to withdraw the plea. Appellant has asserted no valid explanation for his failure to comply with Roberts ; the plea’s validity is thus waived. Commonwealth v. Hughes, 251 Pa.Super. 258, 390 A.2d 811 (1978); Commonwealth v. Heeman, 260 Pa.Super. 79, 393 A.2d 1021 (1978).
Judgment of sentence affirmed.
SPAETH, J., files a dissenting opinion. WATKINS, former President Judge, and HOFFMAN, J., did not participate in the consideration or decision of this case.. 18 Pa.C.S. § 3701.
. 18 Pa.C.S. § 3921.
. 18 Pa.C.S. § 2705.