diff --git a/certificates/essentials/exercises_sudomateo.md b/certificates/essentials/exercises_sudomateo.md
index d93097f..2f6a1ae 100644
--- a/certificates/essentials/exercises_sudomateo.md
+++ b/certificates/essentials/exercises_sudomateo.md
@@ -25,7 +25,7 @@
     2. `chmod 400 file02`
     3. `chmod 651 file03`
     4. `chmod 4744 file04`
-    5. `chmod 4664 file06`
+    5. `chmod 4664 file05`
     6. `chmod 1444 file06`
 5. Run the command `ls -l`. You should see output similar to the following.