diff --git a/subsys/random/rand32_xoroshiro128.c b/subsys/random/rand32_xoroshiro128.c
index 280d41c08fb..bd793c9bd6c 100644
--- a/subsys/random/rand32_xoroshiro128.c
+++ b/subsys/random/rand32_xoroshiro128.c
@@ -106,7 +106,7 @@ void z_impl_sys_rand_get(void *dst, size_t outlen)
 	while (len < outlen) {
 		ret = xoroshiro128_next();
 		if ((outlen-len) < sizeof(ret)) {
-			blocksize = len;
+			blocksize = outlen - len;
 			(void)memcpy(udst, &ret, blocksize);
 		} else {
 			(*udst++) = ret;