diff --git a/lib/dns/badcache.c b/lib/dns/badcache.c
index 3ef1dfaeb6..64363ea793 100644
--- a/lib/dns/badcache.c
+++ b/lib/dns/badcache.c
@@ -16,6 +16,7 @@
 #include <inttypes.h>
 #include <stdbool.h>
 
+#include <isc/atomic.h>
 #include <isc/buffer.h>
 #include <isc/hash.h>
 #include <isc/log.h>