diff --git a/features/device_key/TESTS/device_key/functionality/main.cpp b/features/device_key/TESTS/device_key/functionality/main.cpp
index ee7a38ee90..fc385e3fec 100644
--- a/features/device_key/TESTS/device_key/functionality/main.cpp
+++ b/features/device_key/TESTS/device_key/functionality/main.cpp
@@ -49,7 +49,6 @@ int inject_dummy_rot_key()
 #if !defined(DEVICE_TRNG)
     uint32_t key[DEVICE_KEY_16BYTE / sizeof(uint32_t)];
 
-    memset(key, 0, DEVICE_KEY_16BYTE);
     memcpy(key, "1234567812345678", DEVICE_KEY_16BYTE);
     int size = DEVICE_KEY_16BYTE;
     DeviceKey& devkey = DeviceKey::get_instance();
diff --git a/features/device_key/source/DeviceKey.cpp b/features/device_key/source/DeviceKey.cpp
index 0d9751ccd0..c07b528dcb 100644
--- a/features/device_key/source/DeviceKey.cpp
+++ b/features/device_key/source/DeviceKey.cpp
@@ -253,12 +253,12 @@ int DeviceKey::generate_key_by_trng(uint32_t *output, size_t& size)
 
     final_size = 0;
     in_size = size;
-    while (DEVICEKEY_SUCCESS == ret && final_size < size) {
+    while (final_size < size) {
 
         ongoing_size = 0;
         ret = trng_get_bytes(&trng_obj, (unsigned char *)pBuffer, in_size, &ongoing_size);
         final_size += ongoing_size;
-        if (DEVICEKEY_SUCCESS != ret) {
+        if (0 != ret) {
             ret = DEVICEKEY_TRNG_ERROR;
             goto finish;
         }