diff --git a/ede-php-autoload-composer.el b/ede-php-autoload-composer.el
index 6e3d618..c77e66f 100644
--- a/ede-php-autoload-composer.el
+++ b/ede-php-autoload-composer.el
@@ -138,6 +138,31 @@ BASE-DIR is the prefix dir to add to each autoload path."
 
     autoloads))
 
+(defun ede-php-autoload-composer--merge-autoload-paths (base-paths new-paths)
+  "Merge two paths in a autoload file in one.
+
+BASE-PATHS and NEW-PATHS are either string opr list of strings.
+
+It will output a list of strings with each of base and new paths in it."
+  (let ((list-base-path (if (stringp base-paths) (list base-paths) base-paths))
+        (list-new-paths (if (stringp new-paths) (list new-paths) new-paths)))
+    (append list-base-path list-new-paths)))
+
+(defun ede-php-autoload-composer--merge-autoload-entries (base-entries new-entries)
+  "Merge two autoload entries (right after the autoload entry).
+
+BASE-ENTRIES and NEW-ENTRIES are the entries to merge."
+  (let ((current-entries base-entries)
+        pair
+        pair-path)
+    (cl-loop for (ns . paths) in new-entries do
+             (setq pair (assoc ns current-entries)
+                   pair-path (cdr pair))
+             (if pair
+                 (setf (cdr pair) (ede-php-autoload-composer--merge-autoload-paths pair-path paths))
+               (setq current-entries (push (cons ns paths) current-entries))))
+    current-entries))
+
 (defun ede-php-autoload-composer-merge-autoloads (base-autoloads new-autoloads)
   "Merge two internal autoload definitions in one.
 
@@ -156,7 +181,7 @@ NEW-AUTOLOADS will be merged into BASE-AUTOLOADS.  BASE-AUTOLOADS will be mutate
 
             autoloads (plist-put autoloads
                                  key
-                                 (append
+                                 (ede-php-autoload-composer--merge-autoload-entries
                                   (plist-get autoloads key)
                                   value))
 
diff --git a/test/ede-php-autoload-composer-test.el b/test/ede-php-autoload-composer-test.el
index 8a263eb..1f6bd1d 100644
--- a/test/ede-php-autoload-composer-test.el
+++ b/test/ede-php-autoload-composer-test.el
@@ -35,10 +35,22 @@
             '(:psr-0 (("Test" . "test/")) :psr-4 (("Test3" . "test3/")))
             '(:psr-0 (("Test2" . "test2/")) :psr-4 (("Test4" . "test4/"))))
 
-           '(:psr-0 (("Test" . "test/")
-                     ("Test2" . "test2/"))
-             :psr-4 (("Test3" . "test3/")
-                     ("Test4" . "test4/"))))))
+           '(:psr-0 (("Test2" . "test2/")
+                     ("Test" . "test/"))
+             :psr-4 (("Test4" . "test4/")
+                     ("Test3" . "test3/"))))))
+
+(ert-deftest ede-php-autoload-composer-merge-autoloads-concats-files-merged-part ()
+  "`ede-php-autoload-composer-merge-autoloads' should merge paths with the same key."
+  (should (equal
+
+           (ede-php-autoload-composer-merge-autoloads
+            '(:psr-0 (("Test" . "test/")) :psr-4 (("Test3" . "test3/")))
+            '(:psr-0 (("Test" . "test2/")) :psr-4 (("Test4" . "test4/"))))
+
+           '(:psr-0 (("Test" .  ("test/" "test2/")))
+             :psr-4 (("Test4" . "test4/")
+                     ("Test3" . "test3/"))))))
 
 (ert-deftest ede-php-autoload-composer-define-visitor ()
   "`:define-visitors' should define a visitor according to its step."