I.
This case is an appeal from a conviction under 26 U.S.C. § 7212(a) for “corruptly” endeavoring to obstruct the due administration of Title 26.1 The appellant, Reeves, was charged in a two-count indictment returned on July 12, 1983, by a federal grand jury sitting in Dallas, Texas. Count I of the indictment charged a violation of the mail fraud statute, 18 U.S.C. § 1341. Count II charged corrupt interference with the Internal Revenue Service, a violation of 26 U.S.C. § 7212(a). Both charges arose from the filing of a “common law lien” by Reeves in the deed records office of the Denton County Courthouse, in Denton, Texas on March 22, 1983, against the residence of Douglas W. LeClaire, a criminal investigator with the Criminal Investigation Division of the Internal Revenue Service.
Reeves’ action toward LeClaire stemmed from LeClaire’s investigation of Reeves’ income tax returns for the years 1979, 1980, and 1981. On December 2, 1982, LeClaire and a fellow investigator, Mark Carmena, drove to Reeves' home outside Terrell, Texas, where they found Reeves and explained their purpose for visiting. Reeves answered questions cooperatively for approximately ten minutes, but refused to answer questions about the ownership of the land he occupied. He terminated the interview and LeClaire and Carmena promptly left the premises. LeClaire issued routine summonses to seven financial institutions for bank records concerning Reeves, sending copies of the summonses to Reeves by certified mail. Reeves did not attempt to quash the summonses, but on *997March 8, 1983, executed a common law lien against the residence of Agent LeClaire and recorded it in the Denton County, Texas deeds records office on March 22, 1983. This lien purported to attach to LeClaire’s residence and demanded payment of $250,-000.
Reeves waived his right to a trial by jury and was tried before the bench on March 20 and 21, 1984. At trial LeClaire testified that he and his family had been substantially upset by the lien, although he made no effort to remove it until after Reeves’ prosecution. LeClaire also stated that the lien had interfered with his efforts to sell his house.
Reeves maintained at trial that he had placed the lien in preparation for a suit he planned to bring against LeClaire and the IRS for violation of his constitutional rights. The trial court rejected this argument and held that Reeves’ constitutional claims were frivolous.
Reeves also maintained that he had not placed the lien “corruptly” as that term is used in section 7212(a) and that his behavior was protected by the first amendment’s guarantee of freedom to petition under United States v. Hylton, 710 F.2d 1106 (5th Cir.1983). These claims were also rejected by the court. Following the trial, Reeves was convicted of violation of 26 U.S.C. 7212(a) and sentenced to three years in prison. The district court expressly adopted the definition of “corruptly” as meaning “with improper motive or bad or evil purpose” in convicting Reeves under section 7212(a). Count I of the indictment was dismissed on motion of the government.
Notice of appeal was filed by Reeves on June 13, 1984. On June 13, 1984, he also filed a Rule 35 motion to reduce sentence, and on June 26, 1984, the court reduced Reeves’ sentence to two years in prison.
On appeal, Reeves continues to argue that his filing was not done “corruptly” under section 7212(a). He maintains that the trial court erred in adopting its definition of the term. He also continues to maintain that his behavior was protected under the first amendment.
The government asserts that the trial court’s definition of “corruptly” is correct, relying on cases decided under 18 U.S.C. § 1503 and § 1505, which contain language substantially similar to the language of section 7212(a).2 The government also con*998tends that Hylton does not extend to the protection of the filings of frivolous actions such as the one in this case.
Because our review of the language of section 7212(a), its legislative history, and the constitutional considerations relevant to this case convinces us that the district court erred in adopting the definition of “corruptly” as meaning “with improper motive or bad or evil purpose,” we reverse Reeves’ conviction and remand this case to the district court for reconsideration consistent with our holding here.
II.
A.
We turn first to the language of the statute. Without a clearly expressed legislative intention to the contrary, statutory language must usually be considered controlling. Escondido Mutual Water v. La Jolla, — U.S. —, 104 S.Ct. 2105, 80 L.Ed.2d 753 (1984).
On its face, the statute condemns those who “corruptly” endeavor to intimidate or impede certain government agents or in any other way “corruptly” endeavor to obstruct or impede the due administration of the title; we must therefore determine what “corruptly” means in this context.
It is unlikely that “corruptly” merely means “intentionally” or “with improper motive or bad or evil purpose.” First, the word “endeavor” already carries the requirement of intent; one cannot “endeav- or” what one does not already “intend.” Similarly, the mere purpose of obstructing the tax laws is “improper” and “bad”; therefore, to interpret “corruptly” to mean either “intentionally” or “with an improper motive or bad or evil purpose” is to render “corruptly” redundant. A statute should be read to avoid rendering its language redundant if reasonably possible. Meltzer v. Board of Public Instruction, 548 F.2d 559 n. 38 (5th Cir.1977). This is especially true in the present case where “the key words in the statute are ‘corruptly’ and ‘endeavors.’ ” United States v. Cioffi, 493 F.2d 1111, 1118 (2d Cir.1974) (interpreting 18 U.S.C. § 1503). “Corruptly” is a word with strong connotations; it is difficult to believe Congress included this “key” word only to have it read out of the statute or absorbed into the meaning of “endeavor.”
We have found no cases interpreting the word “corruptly” in section 7212, but cases interpreting analogous sections of the United States Code have interpreted “corruptly” not to mean “with improper motive or bad or evil purpose.” In the case most closely on point, United States v. Ogle, 613 F.2d 233 (10th Cir.1979), the defendant contended that the jury instructions in that case “should have included reference to an evil motive, something bad, wicked or having an evil purpose.” Ogle at 238. The court disagreed, pointing out that “corruptly” is not used in this fashion in 18 U.S.C. § 1503, the statute at issue in that case. “The term ‘corruptly’ does not superimpose a[n] ... element ... such as a desire to undermine the moral character of a juror. Rather, it is directed to the effort to bring about a particular result such as affecting the verdict of a jury or the testimony of a witness____” Id. at 239. “Corruptly” ordinarily describes “[a]n act done with an intent to give some advantage inconsistent with the official duty and rights of others____ It includes bribery but is more comprehensive, because an act may be corruptly done though the advantage to be derived from it be not offered by another.” Id., at 238 (emphasis added). Similarly, the language of section 7212(a) is not directed at actions motivated by all “bad,” “evil” or “improper” purposes; rather, section 7212(a) is directed at efforts to bring about a particular advantage such as impeding the collection of one’s taxes, the taxes of another, or the auditing of one’s or another’s tax records. It is therefore unlikely that the interpretation of “corruptly” as meaning “with improper motive or bad or evil purpose” is an accurate interpretation *999of the meaning of the word as it is used in section 7212(a).
Although the special considerations surrounding a criminal trial have caused courts interpreting section 1503 to impute “corrupt” intent to many practices, the independent significance of this term has not been suppressed. Thus, “to obstruct or impede the due administration of justice is per se unlawful and is tantamount to doing the act corruptly.” Ogle at 238 (emphasis added). Thus, where a defendant has endeavored to obstruct a criminal proceeding, the “advantage inconsistent with the duties and rights of others” is so clear that courts have often been willing to impute the desire to obtain such advantage on a per se basis. Nevertheless, the requirement that the obstruction be done “corruptly” remains of independent significance. It is true that any endeavor to obstruct justice if accompanied by the requisite corrupt intent can be a violation of section 1503, and that the corrupt intent may often be inferred from the endeavor itself. United States v. Howard, 569 F.2d 1331 (5th Cir.1978). Such “endeavors” need not involve force or threats of force; in this sense section 1503 and section 1505 have been given a “broad and all-inclusive meaning.” United States v. Browning, 630 F.2d 694, 701 (10th Cir.1980). But this does not mean the statutes are to be given a sweep beyond the meaning of their language. Criminal statutes are to be strictly construed, Federal Maritime Comm. v. Seatrain Lines, 411 U.S. 726, 93 S.Ct. 1773, 36 L.Ed.2d 620 (1973); and sections 1503, 1505 and 7212(a) are certainly not exceptions to this rule. United States v. Baker, 494 F.2d 1262 (6th Cir.1974) (holding that section 1503 is to be strictly construed). A strict construction of the statute will not permit one of its “key” words to be virtually suppressed.
The special circumstances surrounding criminal proceedings which render many acts to obstruct justice per se corrupt do not exist in cases involving the Internal Revenue Service. Section 1503 covers only conduct that is related to a pending judicial proceeding. Howard at 1336 n. 9. Thus, section 1503 presupposes a proceeding the disruption of which will almost necessarily result in an improper advantage to one side in the case. Because interference with the administration of the tax laws need not concern a proceeding in which a party stands to gain an improper advantage, there is no reason to presume that every annoyance or impeding of an IRS agent is done per se “corruptly.” A disgruntled taxpayer may annoy a revenue agent.with no intent to gain any advantage or benefit other than the satisfaction of annoying the agent. Such actions by taxpayers are not to be condoned, but neither are they “corrupt” under section 7212(a). In such circumstances the agent will normally have a state civil remedy against the taxpayer. If the taxpayer’s actions involve force or the threat of force, they violate section 7212(a)’s prohibition against such behavior.
In addition, we have upheld section 1503 as not unconstitutional on vagueness grounds largely because the statute covers only actions related to pending judicial proceedings, thus providing adequate notice to potential violators. Howard at 1336 n. 9. In contrast, the Internal Revenue Service is permitted great power to intrude on, and investigate virtually every aspect of economic life to effect its purpose of administering the tax laws; thus, the narrow circumstances in which section 1503 applies have no parallel in cases involving section 7212(a). We have noted in the past that except for those narrow circumstances “we would tend to agree with the ... claim that the statute [1503] ... is unconstitutionally vague.” Howard at 1336. Since section 7212(a) is not restrained by the fact that it is narrowly applicable, we cannot say with as much assurance that potential violators will be put on notice that their conduct is “corrupt” in the eyes of the law by the context involved as is the case under section 1503. Accordingly, we are obligated to interpret section 7212(a) to specifically insure that potential violators will be on notice of what constitutes corrupt behavior under section 7212(a); merely prohibiting “bad,” “evil” and “improper” purposes is *1000very probably insufficient where, as here, a statute reaches such a broad category of circumstances.
The government’s reliance on cases in which jury instructions defining “corruptly” as “with improper motive or bad or evil purpose” under the “plain error” standard is misplaced. In United States v. Partin, 552 F.2d 621 (5th Cir.1977) and United States v. Abrams, 427 F.2d 86 (2d Cir.1970), the defendants failed to object to jury instructions defining “corruptly” at trial. Where a defendant fails to object to a jury instruction at trial and raises the issue first on appeal, an appellate court will uphold even an inaccurate jury instruction provided no “plain error” has resulted from the inaccuracy. United States v. Abravaya, 616 F.2d 250 (5th Cir.1980). On appeal the defendants in both cases argued that the instructions permitted conviction even on a finding that the defendants’ “endeav- or” had only been to “influence” the juror or witness to act according to his duties. The appellate courts affirmed the convictions, holding that the instructions did not permit conviction for such wholly innocent behavior, and accordingly that no “plain error” resulted. This, court remarked in Partin that the jury instructions in that case were not well phrased and the issue of whether “corruptly” means “with improper motive and bad or evil purpose” was not raised at all. Partin at 643. Partin cannot be read as a blanket affirmation of the jury instruction given in that case; and, in addition, the differences between the circumstances in which section 1503 applies and those in which section 7212(a) applies, discussed above, warrant interpreting section 7212(a) to make more explicit its requirement of corrupt intent.
The present case is not to be reviewed under the “plain error” standard; here the trial was before the bench and the court adopted its construction of the statute over the defendant’s objections. Under these circumstances an appellate court cannot affirm a conviction predicated on an inaccurate interpretation of the law unless the inaccuracy was harmless error. United States v. Mackey, 571 F.2d 376 (7th Cir.1978).3
B.
The legislative history supports an interpretation of section 7212(a) as forbidding endeavors intended to give “some advantage inconsistent with the rights and duties of others” under the tax laws. The Senate report on the bill which became section 7212 gives only one example of what the statute means by “corruptly endeavor”: corrupt solicitation.4 The term “corruptly *1001endeavor” is broader than corrupt solicitation, but corrupt solicitation is a paradigm of a corrupt endeavor. Ogle. The statute’s broad prohibition against corrupt endeavors should be construed to prohibit those acts substantially similar in result to the offenses expressly mentioned. Howard at 1333; see also United States v. Griffin, 589 F.2d 200 (5th Cir.1979) (both interpreting language of 18 U.S.C. § 1503). The House bill is described by the Senate report as identical to the Senate bill with the exception of the Senate’s addition of a new definition and a new maximum penalty for the use of threats of force; the two bills coincided on their definitions of “corruptly.” Accordingly, the legislative history of section 7212(a) supports interpreting its prohibition against “corruptly” endeavoring to impede or obstruct Title 26 as forbidding those acts done with the intent to secure an unlawful benefit either for oneself or for another.
C.
The definition of “corruptly” as meaning “with improper motive or bad or evil purpose” could potentially raise a question about the overbreadth of section 7212(a) as well as the question of vagueness touched on above. We construe section 7212(a) in order to avoid raising the possibility of “overbreadth” problems under the first amendment. This court has held that the filing of a nonfrivolous criminal complaint against the agents of the Internal Revenue Service is protected under the first amendment even where the filing is motivated by a bad or improper desire to impede the agents’ investigation: “[W]e consider it irrelevant to the applicability of the right to petition [guaranteed by the first amendment] that its exercise might have the effect of causing ... injury to ... [an] official ... or even that the complainer may be aware of or pleased by the prospect of such injury.” United States v. Hylton, 710 F.2d 1106, 1112 (5th Cir.1983) (quoting Stern v. United States Gypsum, 547 F.2d 1329, 1343 (7th Cir.1977)).
Thus, even if the filing of a frivolous common law lien is not protected by the first amendment guarantee of freedom to petition, such filings are at least adjacent to areas of protected activity. It is possible that where the filer has a “bad” motive, the only factor distinguishing a protected from an unprotected filing would be the frivolousness of the lien were we to adopt the trial court’s definition of “corruptly.” In addressing the free speech guarantee of the first amendment, the Court has noted that overbreadth is possible where conduct “falls close to the line separating the lawful and unlawful, the possibility of mistaken fact-finding — inherent in all litigation— will create the danger that ... legitimate ... [action] will be penalized.” Speiser v. Randall, 357 U.S. 513, 526, 78 S.Ct. 1332, 1342, 2 L.Ed.2d 1460 (1958). Similar considerations apply to the guarantee of freedom to petition. To interpret “corruptly” as meaning “with an improper motive or bad or evil purpose” would raise the potential of “overbreadth” in this statute because of the potential chilling effect on protected activities. “[T]he Court has a duty to construe a federal statute to avoid constitutional questions where such a construction is reasonably possible.” Arnett v. Kennedy, 416 U.S. 134, 94 S.Ct. 1633, 40 L.Ed.2d 15 (1974). This constitutionally based duty reaffirms our interpretation of the language of the statute and its legislative history. Where “corruptly” is taken to require an intent to secure an unlawful advantage or benefit, the statute does not infringe on first amendment guarantees and is not “overbroad.” See Bill Johnson’s Restaurants v. NLRB, 461 U.S. 731, 103 S.Ct. 2161, 76 L.Ed.2d 277 (1983); Broadrick v. Oklahoma, 413 U.S. 601, 93 S.Ct. 2908, 37 L.Ed.2d 830 (1973).
III.
We hold that the filing of frivolous common law liens with the intention of *1002securing improper benefits or advantages for one’s self or for others constitutes a prohibited corrupt endeavor under section 7212(a). In the present case it may be that Reeves meant to impede or intimidate officers or agents of the Internal Revenue Service from collecting his just debt of taxes due or from scrutinizing his tax accounts; or it may be that he engaged in this conduct to secure an improper advantage or benefit for other unnamed persons or groups of persons. If this is the case, his actions constituted a corrupt endeavor under section 7212(a).
However, the district court expressly adopted the definition of “corruptly” as meaning “with improper motive or bad or wicked purpose” over the defendant’s objections. In these circumstances we cannot say that the court’s definition constituted harmless error. Accordingly, we reverse Reeves’ conviction and remand the case to the trial court for reconsideration consistent with our holding here. We express no opinion on whether a new trial is necessary, but leave this to the sound discretion of the district court.
REVERSED and REMANDED.