diff --git a/src/shell/tp.md b/src/shell/tp.md
index e8e3438..1c568c1 100644
--- a/src/shell/tp.md
+++ b/src/shell/tp.md
@@ -75,7 +75,7 @@
       exit 1
     fi
 
-    NB_NOTICES=`cat $1 | grep "<exodic " | wc -l`
+    NB_NOTICES=$(cat $1 | grep "<exodic " | wc -l)
 
     echo Nombre de notices dans $1: ${NB_NOTICES}
     ```
@@ -106,7 +106,7 @@
       exit 2
     fi
 
-    NB_NOTICES=`cat $1 | grep "<exodic " | wc -l`
+    NB_NOTICES=$(cat $1 | grep "<exodic " | wc -l)
 
     echo Nombre de notices dans $1: ${NB_NOTICES} > resultats.txt
     ```