diff --git a/dtool/src/prc/notify.cxx b/dtool/src/prc/notify.cxx
index 690910ef4a..9c2ea8b79a 100644
--- a/dtool/src/prc/notify.cxx
+++ b/dtool/src/prc/notify.cxx
@@ -19,9 +19,12 @@
 #include "filename.h"
 #include "config_prc.h"
 
-#include <atomic>
 #include <ctype.h>
 
+#ifdef PHAVE_ATOMIC
+#include <atomic>
+#endif
+
 #ifdef BUILD_IPHONE
 #include <fcntl.h>
 #endif