diff --git a/exwm-randr.el b/exwm-randr.el
index e15d43f..8d1824b 100644
--- a/exwm-randr.el
+++ b/exwm-randr.el
@@ -52,6 +52,8 @@
 (require 'exwm-core)
 (require 'exwm-workspace)
 
+(declare-function x-get-atom-name "C source code" (VALUE &optional FRAME))
+
 (defgroup exwm-randr nil
   "RandR."
   :version "25.3"
diff --git a/exwm.el b/exwm.el
index 369d9c8..4d6b451 100644
--- a/exwm.el
+++ b/exwm.el
@@ -72,6 +72,8 @@
 (require 'exwm-manage)
 (require 'exwm-input)
 
+(declare-function x-get-atom-name "C source code" (VALUE &optional FRAME))
+
 (defgroup exwm nil
   "Emacs X Window Manager."
   :tag "EXWM"