diff --git a/sys/kern/subr_csprng.c b/sys/kern/subr_csprng.c
--- a/sys/kern/subr_csprng.c
+++ b/sys/kern/subr_csprng.c
@@ -201,7 +201,7 @@
 	state->reseed_cnt++;
 
 	for (i = 0; i < 32; i++) {
-		if ((state->reseed_cnt % (1 << i)) != 0)
+		if ((state->reseed_cnt % (1ULL << i)) != 0)
 			break;
 
 		pool = &state->pool[i];