The Fifth Chamber of the European Court of Justice composed of E. Regan, President of the Chamber, I. Jarukaitis, C. Lycourgos, E. Juhász and M. Ilešič, JJ., held that, under Article 5(1) of the Software Directive, lawful software owners are allowed to decompile programmes (in entirety or partially) to remedy flaws that impair the software’s functionality. The request was made as a part of a dispute between Top System SA and the Belgian State1 over the decompilation and forming part of an application of a computer programme developed by Top System for which SELOR, the Selection Office of the Federal Authorities (Belgium) holds a user licence.

Legal context

As mentioned above, the Software Directive (Council Directive 91/250/EEC) was the main legislative statute used by the Bench to reach its decision2.

The said Directive’s Article 4 deals with “Restricted Acts”, which grant creators exclusive rights to reproduce and change computer programmes, but Article 5 enables the licensor to duplicate and alter a programme as needed to utilise it for its intended purpose, including mistake rectification. Furthermore, Article 6 deals with decompilation, allowing the imitation of software code and translation, where doing so is necessary to gain the information needed for interoperability, as long as it is done by the licensee or another authorised user; the information required for interoperability is not commonly accessible to the licensee; and any related measures taken are restricted to those segments of the original software/computer programme required to achieve interoperability.

The dispute in the main proceedings and the questions referred for a preliminary ruling

Top System is a Belgian-based firm that creates computer applications and offers IT services. SELOR is the Belgian State authority in charge of choosing and orienting future workers for the Government’s numerous public services. Top System has worked with SELOR since 1990, providing IT development and maintenance services on their behalf. To carry out its responsibilities, SELOR has gradually implemented IT systems that allow applications to be filed and processed online. Top System’s programs have a user licence that SELOR possesses.

On 6-2-2008, SELOR and Top System signed a contract for the installation and setup of a major development environment, as well as the integration and migration of SELOR’s application sources to the new environment. There was an e-mail conversation between SELOR and Top System concerning operational difficulties impacting certain TSF-based apps between June and October 2008. After failing to reach an agreement with SELOR to resolve those issues, Top System filed a lawsuit against SELOR and the Belgian State in the Tribunal de commerce de Bruxelles (Commercial Court of Brussels, Belgium) on 6-2-2009, seeking, among other things, a declaration that SELOR had decompiled the TSF in violation of Top System’s exclusive rights in that software. Top System further claimed that SELOR and the Belgian State should be compelled to pay it damages, as well as compensatory interest, for the decompilation and copying of the source codes from that programme, starting from the projected date of that decompilation, which was 18-12-2008.

The matter was sent to the Tribunal de première instance de Bruxelles (Court of First Instance, Brussels, Belgium) on 26-11-2009, which dismissed Top System’s claim by ruling dated 19-3-2013. Top System filed an appeal with the referring court, the cour d’appel de Bruxelles, against that decision (Court of Appeal, Brussels, Belgium). Top System claims that SELOR illegally decompiled the Top System Framework (TSF).  Decompilation, according to the applicant, can only be done with the author’s permission, the author’s successor in title’s permission, or for interoperability considerations.Decompilation, on the other hand, is not authorised for the purpose of fixing mistakes that impact the program’s functionality. SELOR admits to decompiling a portion of the TSF in order to deactivate a faulty function. It claims, among other things, that it was allowed to do the decompilation in order to fix specific design flaws in the TSF that rendered it impossible to utilise the programme for its “intended purpose”.

SELOR also focuses on its right to watch, analyse, or test the operation of the programme in question in order to determine the underlying concepts and principles of the necessary TSF functions and therefore, avoid the blockages produced by such mistakes. The referring court believes that it is for that court to assess whether SELOR was authorised to carry out such decompilation and if such decompilation is legitimate at all or not.

Questions referred

  1. Whether Article 5(1) of the Software Directive can be interpreted to allow a lawful customer of a computer programme to decompile all or part of the programme in order to fix discrepancies impacting the program’s operation, including circumstances where the correction consists of disabling a component that is affecting the efficient functioning of the application?
  2. If that question is answered affirmatively, must the conditions set forth in Article 6 of the Directive, as well as any additional circumstances, also be met?

Analysis and findings of the court

The ECJ held in Top System that, under an interpretation of Article 5, a legitimate buyer of a computer programme is permitted to decompile the software (in whole or in part) in order to rectify faults affecting its function, without having to comply with Article 6 obligations. The licensee would be prohibited from using the decompiled programme for anything other than error rectification. Unless the licence prohibits it, a licensee can decompile a computer programme to rectify flaws, according to the Advocate General’s decision in the case. The independence of Articles 5 and 6, as well as the potential of decompilation under Articles 5 and 6, were emphasised in the judgment.

In particular, the decision said that, irrespective of Article 6 (which allows decompilation), Article 5 should be understood as allowing a licensor to decompile a computer programme in order to fix flaws that impact its functionality. The takeaway from this ECJ decision is that a computer programme can be decompiled to repair a mistake under Article 5, and that this right is separate from the right to decompile a software for interoperability under Article 6. While the decision should not be seen as opening the floodgates for software decompilation, it does provide useful clarification regarding the rights and duties of both the licensor and the licensee when it comes to addressing software flaws.7

While this has the potential to be extremely important, the actuality will be determined only by how strict the regulations are. What will be fascinating to see how broad or limited the interpretation of this decision8 will be in the future. Scholars have also pointed out how this presents a slew of new problems, such as what it “truly” means to “impair the software’s functioning”. Questions have also been raised about how this judgment can be used to patch out any kind of technological protection measures, or TPMs, which was also mentioned in a 2014 judgment by the European Court of Justice, which held that circumventing TPMs and digital rights management tools (DRMs) could be legal in certain circumstances.11 Surprisingly, in 2010, a Federal Appeals Court in the United States had ruled that bypassing DRMs for “fair use” was permissible as well.12 Furthermore, the US Government had also ruled in 2018 that circumventing DRMs and TPMs to repair electronic devices was permissible, propelling this narrative even further.13 A recent example of the same was witnessed in March 2021, when an individual successfully decompiled and improved a popular online game titled Grand Theft Auto V. Interestingly, the player was rewarded $10,000 USD by the game’s developers too.14

Others were also critical about how this decision15 may affect anti-tampering measures integrated into software, as well as their influence on vital applications such as banking software. In this regard, it is worth noting that the judgment16 and the legislation effectively indicate that, in the absence of a particular contractual provision, the legitimate purchaser of software should be able to transfer the programme into the State to allow it to serve its “intended purpose”.  Anti-tampering would still be acceptable if it is combined with a contractual term that name the licence seller as the buyer’s exclusive source of remedy for getting the programme rectified if there are any problems with it.

As a result, the ECJ has recommended that the procedure for rectifying software faults be addressed in the licence and contract provisions to reduce conflicts surrounding the decompilation of licensed software. Although the parties are not allowed to completely rule out the possibility of rectifying flaws, a contractual agreement will allow licensees and licensors to choose the manner that best suits their individual goals.


All in all, it is important to note that the decision is not relevant because of a supposed “right to repair”. The right to repair has been enshrined in European Directives for decades, and it has existed on national and international levels for even longer. The judgment is significant because it expressly says that decompilation is permitted in the exercise of the right to repair which is of great importance from a consumer’s perspective. With that being said, its real world application will be apparent only as time progresses.

*Student, Symbiosis Law School, Pune. Author can be reached at

1Top System SA v. Belgian State, Case C‑13/20, decided on 6-10-2021.

2Top System SA v. Belgian State, Case C‑13/20, decided on 6-10-2021.

7Cynthia O’Donoghue, ECJ Top System Ruling Grants Right to Correct Software Errors, Reed Smith (15-10-2021, 10:04A.M.) <>.

8Top System SA v. Belgian State, Case C‑13/20, decided on 6-10-2021.

11Glyn Moody, Europe’s Highest Court Says DRM Circumvention May be Lawful in Certain Circumstances, TechDirt (15-10-2021, 10:04A.M.) <>.

12Matthew Lasar, Court: Breaking DRM for a “Fair Use” is Legal, ArsTechnica (15-10-2021, 10:04A.M.) <>.

13Paul Lilly, US Government Deems it Legal to Circumvent DRM to Repair Electronic Devices, PCGamer (15-10-2021, 10:04A.M.) <>.

14Matthew Humphries, Rockstar Rewards Player Who Cut GTA Online Load Times by 70% with $10K, PCMag (15-10-2021, 10:04A.M.) <>.

15Top System SA v. Belgian State, Case C‑13/20, decided on 6-10-2021.

16Top System SA v. Belgian State, Case C‑13/20, decided on 6-10-2021.

Must Watch

maintenance to second wife

bail in false pretext of marriage

right to procreate of convict

Criminology, Penology and Victimology book release

Join the discussion

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.