diff --git a/http/query_string.h b/http/query_string.h
index 6fed49a..e980280 100644
--- a/http/query_string.h
+++ b/http/query_string.h
@@ -203,7 +203,7 @@
                 qs[i] = '\0';
                 return i;
             }
-            qs[i] = static_cast<char>(BMCWEB_QS_HEX2DEC(qs[j + 1] * 16) +
+            qs[i] = static_cast<char>((BMCWEB_QS_HEX2DEC(qs[j + 1]) * 16) +
                                       BMCWEB_QS_HEX2DEC(qs[j + 2]));
             j += 2;
         }