diff --git a/tests/suites/test_suite_alignment.function b/tests/suites/test_suite_alignment.function
index 717c51a69..ed8f918d8 100644
--- a/tests/suites/test_suite_alignment.function
+++ b/tests/suites/test_suite_alignment.function
@@ -12,7 +12,7 @@
  */
 int parse_hex_string(char *hex_string, uint64_t *result)
 {
-    uint8_t raw[8];
+    uint8_t raw[8] = {0};
     size_t olen;
     if (mbedtls_test_unhexify(raw, sizeof(raw), hex_string, &olen) != 0) {
         return 0;
@@ -104,7 +104,7 @@ void mbedtls_unaligned_access(int size, int offset)
 /* BEGIN_CASE */
 void mbedtls_byteswap(char *input_str, int size, char *expected_str)
 {
-    uint64_t input, expected;
+    uint64_t input = 0, expected = 0;
     TEST_ASSERT(parse_hex_string(input_str, &input));
     TEST_ASSERT(parse_hex_string(expected_str, &expected));