diff --git a/tests/unit/test-api.c b/tests/unit/test-api.c
index b2aea32fc..41564cde6 100644
--- a/tests/unit/test-api.c
+++ b/tests/unit/test-api.c
@@ -71,7 +71,8 @@ handler (const jerry_value_t func_obj_val, /**< function object */
   char buffer[32];
   jerry_size_t sz;
 
-  printf ("ok %d %d %p %d\n", func_obj_val, this_val, args_p, args_cnt);
+  printf ("ok %u %u %p %u\n",
+          (unsigned int) func_obj_val, (unsigned int) this_val, (void *) args_p, (unsigned int) args_cnt);
 
   TEST_ASSERT (args_cnt == 2);
 
@@ -95,7 +96,8 @@ handler_throw_test (const jerry_value_t func_obj_val, /**< function object */
                     const jerry_value_t args_p[], /**< arguments list */
                     const jerry_length_t args_cnt) /**< arguments length */
 {
-  printf ("ok %d %d %p %d\n", func_obj_val, this_val, args_p, args_cnt);
+  printf ("ok %u %u %p %u\n",
+          (unsigned int) func_obj_val, (unsigned int) this_val, (void *) args_p, (unsigned int) args_cnt);
 
   return jerry_create_error (JERRY_ERROR_TYPE, (jerry_char_t *) "error");
 } /* handler_throw_test */
@@ -115,7 +117,8 @@ handler_construct (const jerry_value_t func_obj_val, /**< function object */
                    const jerry_value_t args_p[], /**< arguments list */
                    const jerry_length_t args_cnt) /**< arguments length */
 {
-  printf ("ok construct %d %d %p %d\n", func_obj_val, this_val, args_p, args_cnt);
+  printf ("ok construct %u %u %p %u\n",
+          (unsigned int) func_obj_val, (unsigned int) this_val, (void *) args_p, (unsigned int) args_cnt);
 
   TEST_ASSERT (jerry_value_is_object (this_val));
 
diff --git a/tests/unit/test-libm.c b/tests/unit/test-libm.c
index a11a13018..0b53966c9 100644
--- a/tests/unit/test-libm.c
+++ b/tests/unit/test-libm.c
@@ -33,13 +33,25 @@ check_int (const char *expr, int computed, int expected)
   passed &= result;
 } /* check_int */
 
+typedef union
+{
+  double value;
+  uint64_t bits64;
+  uint32_t bits32[2];
+} double_bits_t;
+
 static void
 check_double (const char *expr, double computed, double expected)
 {
-  uint64_t *computed_bits_p = (uint64_t *) &computed;
-  uint64_t *expected_bits_p = (uint64_t *) &expected;
+  double_bits_t computed_bits;
+  double_bits_t expected_bits;
 
-  printf ("%s = 0x%lx [expected=0x%lx] ", expr, *computed_bits_p, *expected_bits_p);
+  computed_bits.value = computed;
+  expected_bits.value = expected;
+
+  printf ("%s = 0x%08x%08x [expected=0x%08x%08x] ", expr,
+          (unsigned int) computed_bits.bits32[1], (unsigned int) computed_bits.bits32[0],
+          (unsigned int) expected_bits.bits32[1], (unsigned int) expected_bits.bits32[0]);
 
   bool result;
   if (isnan (computed) && isnan (expected))
@@ -48,7 +60,7 @@ check_double (const char *expr, double computed, double expected)
   }
   else
   {
-    int64_t diff = (int64_t) (*computed_bits_p - *expected_bits_p);
+    int64_t diff = (int64_t) (computed_bits.bits64 - expected_bits.bits64);
     if (diff < 0)
     {
       diff = -diff;