diff --git a/lib/posix/options/eventfd.c b/lib/posix/options/eventfd.c
index 767cf5a60cc..81b8f6d6dd8 100644
--- a/lib/posix/options/eventfd.c
+++ b/lib/posix/options/eventfd.c
@@ -247,7 +247,9 @@ static int eventfd_ioctl_op(void *obj, unsigned int request, va_list args)
 			errno = EINVAL;
 			ret = -1;
 		} else {
-			efd->flags = flags;
+			int prev_flags = efd->flags & ~EFD_FLAGS_SET_INTERNAL;
+
+			efd->flags = flags | prev_flags;
 			ret = 0;
 		}
 	} break;