diff --git a/test/unittest/platform/common/adc_test.c b/test/unittest/platform/common/adc_test.c
index 166883282a928b83261ff705017368f4b0d6e58f..01355d5fc5d4992699350f86b51dd292a7351735 100644
--- a/test/unittest/platform/common/adc_test.c
+++ b/test/unittest/platform/common/adc_test.c
@@ -112,7 +112,7 @@ int32_t AdcTestRead(void)
     for (i = 0; i < TEST_ADC_VAL_NUM; i++) {
         value[i] = 0;
         ret = AdcRead(tester->handle, tester->config.channel, &value[i]);
-        if (ret != HDF_SUCCESS || value[i] >= (1 << tester->config.dataWidth)) {
+        if (ret != HDF_SUCCESS || value[i] >= (1U << tester->config.dataWidth)) {
             HDF_LOGE("%s: read value invalid:%u, ret:%d", __func__, value[i], ret);
             return HDF_ERR_IO;
         }