diff --git a/helpers/helpers.v1.d/templating b/helpers/helpers.v1.d/templating
index 76f319137a..254f11463d 100644
--- a/helpers/helpers.v1.d/templating
+++ b/helpers/helpers.v1.d/templating
@@ -267,7 +267,7 @@ ynh_read_var_in_file() {
     var_part+='\s*'
 
     # Extract the part after assignation sign
-    local expression_with_comment="$((tail +$line_number ${file} | grep -i -o -P $var_part'\K.*$' || echo YNH_NULL) | head -n1)"
+    local expression_with_comment="$( (tail +$line_number ${file} | grep -i -o -P $var_part'\K.*$' || echo YNH_NULL) | head -n1)"
     if [[ "$expression_with_comment" == "YNH_NULL" ]]; then
         set -o xtrace # set -x
         echo YNH_NULL
@@ -346,7 +346,7 @@ ynh_write_var_in_file() {
     var_part+='\s*'
 
     # Extract the part after assignation sign
-    local expression_with_comment="$((tail +$after_line_number ${file} | grep -i -o -P $var_part'\K.*$' || echo YNH_NULL) | head -n1)"
+    local expression_with_comment="$( (tail +$after_line_number ${file} | grep -i -o -P $var_part'\K.*$' || echo YNH_NULL) | head -n1)"
     if [[ "$expression_with_comment" == "YNH_NULL" ]]; then
         set -o xtrace # set -x
         return 1
diff --git a/helpers/helpers.v2.1.d/templating b/helpers/helpers.v2.1.d/templating
index dc7a090a26..a00cf18caa 100644
--- a/helpers/helpers.v2.1.d/templating
+++ b/helpers/helpers.v2.1.d/templating
@@ -216,7 +216,7 @@ ynh_read_var_in_file() {
     var_part+='\s*'
 
     # Extract the part after assignation sign
-    local expression_with_comment="$((tail +$line_number ${file} | grep -i -o -P $var_part'\K.*$' || echo YNH_NULL) | head -n1)"
+    local expression_with_comment="$( (tail +$line_number ${file} | grep -i -o -P $var_part'\K.*$' || echo YNH_NULL) | head -n1)"
     if [[ "$expression_with_comment" == "YNH_NULL" ]]; then
         set -o xtrace # set -x
         echo YNH_NULL
@@ -292,7 +292,7 @@ ynh_write_var_in_file() {
     var_part+='\s*'
 
     # Extract the part after assignation sign
-    local expression_with_comment="$((tail +$after_line_number ${file} | grep -i -o -P $var_part'\K.*$' || echo YNH_NULL) | head -n1)"
+    local expression_with_comment="$( (tail +$after_line_number ${file} | grep -i -o -P $var_part'\K.*$' || echo YNH_NULL) | head -n1)"
     if [[ "$expression_with_comment" == "YNH_NULL" ]]; then
         set -o xtrace # set -x
         return 1