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Exhibit 3.1

AMENDMENT TO ARTICLES OF INCORPORATION DATED JUNE 24, 2004

|[logo] | Industry Canada  | Industrie Canada        
|------ | ---------------- | ------------------------
|      
|       | Certificate      | Certificat              
|       | of Amendment     | de modification         
|      
|       | Canada Business  | Loi canadienne sur      
|       | Corporations Act | les sociétés par actions

COGNOS INCORPORATED

|                                                                                                                                            
|--------------------------------------------------------------------------------------------------------------------------------------------
|COGNOS INCORPORÉE                                                                                                                           
|                                                                                                                                            
|                                                                                                                                            
|Name of corporation  Dénomination de la société                                                                                            
|                                                                                                                                            
|I hereby certify that the articles of the
above-named corporation were amended:                                                             
|                                                                                                                                            
|(a) under section 13 of the Canada Business
Corporations Actin accordance with the attached
notice;                                         
|                                                                                                                                            
|(b) under section 27 of the Canada Business
Corporations Actas set out in the attached
articles of amendment designating a series of
shares;
|                                                                                                                                            
|(c) under section 179 of the Canada Business
Corporations Actas set out in the attached
articles of amendment;                              
|                                                                                                                                            
|(d) under section 191 of the Canada Business
Corporations Actas set out in the attached
Articles of Reorganization;                         
|                                                                                                                                            
|[SIGNATURE]                                                                                                                                 
|Director / Directeur                                                                                                                        

[LOGO]

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|[logo] | Industry Canada  | Industrie Canada         |                       |                       
|------ | ---------------- | ------------------------ | --------------------- | ----------------------
|       |                  |                          | FORM 4                | FORMULE 4             
|       | Canada Business  | Loi canadienne sur       | ARTICLES OF AMENDMENT | CLAUSES MODIFICATRICES
|       | Corporations Act | les sociétés par actions | (SECTION 27 OR 177)   | (ARTICLES 27 OU 177)  



|                                                                          
|--------------------------------------------------------------------------
|1  Name of Corporation  Dénomination de la société                      
|COGNOS INCORPORATED                                                       
|COGNOS INCORPORÉE                                                         
|                                                                          
|3  The articles of the above-named corporation are
   amended as follows:

The Articles of Incorporation of the
Corporation be amended to eliminate the preferred class of shares by deleting Paragraph
3(2) thereof.

|                                
|--------------------------------
|Date                            
|June 24, 2004                   
|                                
|For Departmental use only       
|À l'usage du Ministère seulement
|Filed June 24, 2004             
|Déposée                         
|                                

49