diff --git a/composer.json b/composer.json
index 35ca259a..b6db82a4 100644
--- a/composer.json
+++ b/composer.json
@@ -37,9 +37,9 @@
         ]
     },
     "autoload": {
-        "psr-4": {
-            "": "src/"
-        },
+        "classmap": [
+            "src/"
+        ],
         "files": [
             "search-replace-command.php"
         ]