diff --git a/app/src/rng.c b/app/src/rng.c
index 2f43ac6..a009854 100644
--- a/app/src/rng.c
+++ b/app/src/rng.c
@@ -9,7 +9,12 @@ static uint8_t buffer[64];
 char buffer_ascii[sizeof buffer * 2 + 1];
 
 static int rng_test(const struct shell *sh) {
+#if CONFIG_TWPM_USE_UNSAFE_RNG
+	sys_rand_get(buffer, sizeof buffer);
+	int ret = 0;
+#else
 	int ret = sys_csrand_get(buffer, sizeof buffer);
+#endif
 	if (ret == 0) {
 		for (int i = 0; i < sizeof buffer; i++) {
 			uint8_t t;