diff --git a/features/device_key/source/DeviceKey.cpp b/features/device_key/source/DeviceKey.cpp
index 3d9b8dac07..7491add70a 100644
--- a/features/device_key/source/DeviceKey.cpp
+++ b/features/device_key/source/DeviceKey.cpp
@@ -260,7 +260,7 @@ int DeviceKey::generate_key_by_random(uint32_t *output, size_t size)
         return DEVICEKEY_INVALID_PARAM;
     }
 
-#if DEVICE_TRNG
+#if defined(DEVICE_TRNG) || defined(MBEDTLS_ENTROPY_NV_SEED)
     uint32_t test_buff[DEVICE_KEY_32BYTE / sizeof(int)];
     mbedtls_entropy_context *entropy = new mbedtls_entropy_context;
     mbedtls_entropy_init(entropy);
@@ -276,6 +276,7 @@ int DeviceKey::generate_key_by_random(uint32_t *output, size_t size)
 
     mbedtls_entropy_free(entropy);
     delete entropy;
+
 #endif
 
     return ret;