diff --git a/db/plain_table_db_test.cc b/db/plain_table_db_test.cc
index ff07def9690b60ffb6fbacef0d6bb074bca73f53..e3d9fc40217eb54d37cfeb040a098d2721c2160b 100644
--- a/db/plain_table_db_test.cc
+++ b/db/plain_table_db_test.cc
@@ -68,7 +68,7 @@ TEST_F(PlainTableKeyDecoderTest, ReadNonMmap) {
       ASSERT_EQ(0, out.compare(tmp.substr(pos, read_size)));
     }
 
-    ASSERT_LT(string_source->total_reads(), kLength / kReadSize / 2);
+    ASSERT_LT(uint32_t(string_source->total_reads()), kLength / kReadSize / 2);
   }
 
   std::vector<std::vector<std::pair<uint32_t, uint32_t>>> reads = {