diff --git a/external/nng/src/platform/posix/posix_thread.c b/external/nng/src/platform/posix/posix_thread.c
index 7d68759..29e06a1 100644
--- a/external/nng/src/platform/posix/posix_thread.c
+++ b/external/nng/src/platform/posix/posix_thread.c
@@ -379,7 +379,7 @@ nni_plat_init(int (*helper)(void))
 	struct rlimit rl;
 	if ((getrlimit(RLIMIT_STACK, &rl) == 0) &&
 	    (rl.rlim_cur != RLIM_INFINITY) &&
-	    (rl.rlim_cur >= PTHREAD_STACK_MIN) &&
+	    (rl.rlim_cur >= (rlim_t)PTHREAD_STACK_MIN) &&
 	    (pthread_attr_setstacksize(&nni_thrattr, rl.rlim_cur) != 0)) {
 		pthread_mutex_unlock(&nni_plat_init_lock);
 		pthread_mutexattr_destroy(&nni_mxattr);