diff --git a/include/random_numbers.h b/include/random_numbers.h
index 77a7ba2..5b3b02b 100644
--- a/include/random_numbers.h
+++ b/include/random_numbers.h
@@ -34,7 +34,7 @@
 #include <sys/syscall.h> // syscall
 #ifdef SYS_getrandom
 #define GRND_NONBLOCK       1
-#include <errno.h>       // errno
+#include <errno.h>       // errno, EAGAIN
 #endif
 #endif