diff --git a/helpers/utils b/helpers/utils
index 60cbedb5c..01a8a1371 100644
--- a/helpers/utils
+++ b/helpers/utils
@@ -513,7 +513,7 @@ ynh_read_var_in_file() {
     # Get the line number after which we search for the variable
     local line_number=1
     if [[ -n "$after" ]]; then
-        line_number=$(grep -n $after $file | cut -d: -f1)
+        line_number=$(grep -m1 -n $after $file | cut -d: -f1)
         if [[ -z "$line_number" ]]; then
             set -o xtrace # set -x
             return 1
@@ -591,7 +591,7 @@ ynh_write_var_in_file() {
     # Get the line number after which we search for the variable
     local line_number=1
     if [[ -n "$after" ]]; then
-        line_number=$(grep -n $after $file | cut -d: -f1)
+        line_number=$(grep -m1 -n $after $file | cut -d: -f1)
         if [[ -z "$line_number" ]]; then
             set -o xtrace # set -x
             return 1