diff --git a/hack/validate-migration.sh b/hack/validate-migration.sh
index 889fc28089..ca03e9a872 100755
--- a/hack/validate-migration.sh
+++ b/hack/validate-migration.sh
@@ -259,11 +259,12 @@ list_migration_files() {
         case "$status" in
             A)  # file is added
                 task_dir_path=$(awk -F '/' '{ OFS = "/"; print $1, $2 }' <<<"$origin_path")
-                if grep -q "$task_dir_path" <<<"$seen"; then
+                if grep -q "^${task_dir_path}$" <<<"$seen"; then
                     echo "error: There must be one migration file per task in a single pull request." >&2
                     return 1
                 else
-                    seen="$seen $task_dir_path"
+                    seen="$seen
+$task_dir_path"
                     echo "$origin_path"
                 fi
                 ;;