Forrest S. Tucker appeals from a district court order denying his motion, made under 28 U.S.C. § 2255, to vacate the judgment convicting him of armed robbery and to set aside the sentence based thereon. The judgment and sentence of imprisonment for twenty-five years, entered on May 20, 1953, was affirmed by this court in Tucker v. United States, 214 F.2d 713 (9th Cir. 1954). The district court opinion now under review in this section 2255 proceeding is reported in 299 F.Supp. 1376 (N.D.Cal. 1969).
After Tucker had testified in his 1953 trial for the armed robbery, the Government introduced evidence of his three prior felony convictions. This evidence was received for the purpose of impeaching Tucker’s own testimony offering an alibi defense. In addition, after the jury had entered its verdict of guilty, the trial judge called for further information, in the form of a Federal Bureau of Investigation report concern*1293ing Tucker’s prior convictions, for use in determining the sentence to be imposed.
On June 10, 1966, the Superior Court of Alameda County, California, in case No. 25,174, set aside two of Tucker’s prior convictions on the ground that “the defendant was neither advised of his rights to legal assistance nor did he intelligently and understandingly waive this right to the assistance of counsel.” The Government concedes that these two prior felony convictions were invalid under Gideon v. Wainwright, 372 U.S. 335, 344-345, 83 S.Ct. 792, 9 L.Ed.2d 799 (1963).
In this section 2255 proceeding Tucker argues that his 1953 conviction is invalid, under the rule of Burgett v. Texas, 389 U.S. 109, 115, 88 S.Ct. 258, 19 L.Ed. 2d 319 (1967), because his prior uncoun-seled convictions were used at his trial to impeach his credibility and to influence the court in imposing sentence.
In Burgett, the Supreme Court stated that
“[t]o permit a conviction obtained in violation of Gideon v. Wainwright to be used against a person either to support guilt or enhance punishment for another offense * * * is to erode the principle of that case.” 389 U.S. at 115, 88 S.Ct. at 262.
This rule is being applied retroactively by this court and other courts of appeals which have had occasion to consider the problem.1
The Burgett rule against the use of uncounseled convictions to prove guilt or enhance punishment precludes the use of such evidence to impeach a defendant’s credibility as a witness. Gilday v. Scafati, 428 F.2d 1027 (1st Cir.1970).2
We are also in agreement with the further ruling in Gilday, for the reasons there stated, that the reception of evidence pertaining to prior convictions, constitutionally erroneous under Burgett may, under the circumstances of a particular case, be harmless beyond a reasonable doubt, applying the principle announced in Chapman v. California, 386 U.S. 18, 24, 87 S.Ct. 824, 17 L.Ed.2d 705 (1967). Under Chapman, an error of constitutional proportions can be disregarded as harmless if the prosecution proves beyond a reasonable doubt that the error “did not contribute to the verdict obtained.” 386 U.S. at 24, 87 S.Ct. at 828.3
The nature of defendant’s testimony at the trial, and the overwhelming weight of the testimony to the contrary are fully described in the district court opinion, 299 F.Supp. 1376, at 1377-1378. We agree with the district court that defendant’s testimony was completely discredited by evidence other than that pertaining to the prior convictions. This leads us to conclude that the prosecution firmly proved that the evidence of prior convictions did not contribute to the verdict obtained and that, with respect to the verdict of guilty, the error in receiving such evidence was therefore harmless beyond a reasonable doubt.
*1294As noted above, the evidence pertaining to Tucker’s prior convictions was submitted not only to affect his credibility as a witness, but also to assist the trial court in fixing the sentence. The twenty-five year prison sentence imposed following Tucker’s conviction for armed robbery, in violation of 18 U.S.C. § 2113(a) and (d), was the maximum allowable under the statute.
There is a reasonable probability that the defective prior convictions may have led the trial court to impose a heavier prison sentence than it otherwise would have imposed. Therefore, as to the sentencing, we are unable to conclude that the reception of such evidence was. harmless beyond a reasonable doubt.
Accordingly, the judgment of conviction is affirmed, but the cause is remanded to the district court for resen-tencing without consideration of any prior convictions which are invalid under Gideon v. Wainwright, 372 U.S. 335, 83 S.Ct. 792, 9 L.Ed.2d 799 (1963).
. See Tucker v. Craven, 421 F.2d 139 (9th Cir. 1970); Gilday v. Scafati, 428 F.2d 1027 (1st Cir. 1970); Oswald v. Crouse, 420 F.2d 373 (10th Cir. 1969); Losieau v. Siegler, 406 F.2d 795 (8th Cir. 1969); Williams v. Coiner, 392 F.2d 210 (4th Cir. 1968). The Gilday opinion contains a good statement of the reasons why Burgett should be applied retroactively.
. The question of whether Burgett precludes use of a prior conviction, invalid under Gideon v. Wainwright, to impeach a defendant’s testimony in a subsequent trial on another charge, was argued in this court in Shorter v. United States, 412 F.2d 428 (9th Cir. 1969). However, in that case we did not decide the question because it was the defendant, and not the prosecution, who offered the evidence pertaining to a prior conviction.
. The Chapman court stated that there is little, if any, difference between this statement of the governing principle, and the statement in Fahy v. Connecticut, 375 U.S. 85, 86-87, 84 S.Ct. 229, 11 L.Ed.2d 171 (1963) that “[t]he question is whether there is a reasonable possibility that the evidence complained of might have contributed to the conviction.” See also, Harrington v. California, 395 U.S. 250, 89 S.Ct. 1726, 23 L.Ed.2d 284 (1969).