diff --git a/lisp/php-flymake.el b/lisp/php-flymake.el
index 54eef1e7..a3650dad 100644
--- a/lisp/php-flymake.el
+++ b/lisp/php-flymake.el
@@ -26,6 +26,7 @@
 
 ;;; Code:
 (require 'flymake)
+(require 'flymake-proc)
 (require 'cl-lib)
 (eval-when-compile
   (require 'pcase)
diff --git a/lisp/php-mode.el b/lisp/php-mode.el
index dd57690b..efcdd2a3 100644
--- a/lisp/php-mode.el
+++ b/lisp/php-mode.el
@@ -83,6 +83,7 @@
   (require 'rx)
   (require 'cl-lib)
   (require 'flymake)
+  (require 'flymake-proc)
   (require 'php-flymake)
   (require 'regexp-opt)
   (declare-function acm-backend-tabnine-candidate-expand "ext:acm-backend-tabnine"