diff --git a/src/ccontrol/UserQueryFactory.cc b/src/ccontrol/UserQueryFactory.cc
index 28479d122..e7cb11f62 100644
--- a/src/ccontrol/UserQueryFactory.cc
+++ b/src/ccontrol/UserQueryFactory.cc
@@ -298,6 +298,11 @@ UserQuery::Ptr UserQueryFactory::newUserQuery(std::string const& aQuery, std::st
         }
         auto stmt = parser->getSelectStmt();
 
+        // Parsing doesn't need protection, but CSS in analyze query does and
+        // some of the uq related calls may require protection, but it
+        // isn't clear.
+        std::lock_guard<std::mutex> factoryLock(_factoryMtx);
+
         // handle special database/table names
         if (_stmtRefersToProcessListTable(stmt, defaultDb)) {
             return _makeUserQueryProcessList(stmt, _userQuerySharedResources, userQueryId, resultDb, aQuery,
@@ -378,12 +383,14 @@ UserQuery::Ptr UserQueryFactory::newUserQuery(std::string const& aQuery, std::st
         }
         return uq;
     } else if (UserQueryType::isSelectResult(query, userJobId)) {
+        std::lock_guard<std::mutex> factoryLock(_factoryMtx);
         auto uq = std::make_shared<UserQueryAsyncResult>(userJobId, _userQuerySharedResources->czarId,
                                                          _userQuerySharedResources->queryMetadata);
         LOGS(_log, LOG_LVL_DEBUG, "make UserQueryAsyncResult: userJobId=" << userJobId);
         return uq;
     } else if (UserQueryType::isShowProcessList(query, full)) {
         LOGS(_log, LOG_LVL_DEBUG, "make UserQueryProcessList: full=" << (full ? 'y' : 'n'));
+        std::lock_guard<std::mutex> factoryLock(_factoryMtx);
         try {
             return std::make_shared<UserQueryProcessList>(full, _userQuerySharedResources->qMetaSelect,
                                                           _userQuerySharedResources->czarId, userQueryId,
@@ -392,10 +399,12 @@ UserQuery::Ptr UserQueryFactory::newUserQuery(std::string const& aQuery, std::st
             return std::make_shared<UserQueryInvalid>(exc.what());
         }
     } else if (UserQueryType::isCall(query)) {
+        std::lock_guard<std::mutex> factoryLock(_factoryMtx);
         auto parser = std::make_shared<ParseRunner>(
                 query, _userQuerySharedResources->makeUserQueryResources(userQueryId, resultDb));
         return parser->getUserQuery();
     } else if (UserQueryType::isSet(query)) {
+        std::lock_guard<std::mutex> factoryLock(_factoryMtx);
         ParseRunner::Ptr parser;
         try {
             parser = std::make_shared<ParseRunner>(query);
@@ -414,6 +423,7 @@ UserQuery::Ptr UserQueryFactory::newUserQuery(std::string const& aQuery, std::st
         }
         return uq;
     } else {
+        std::lock_guard<std::mutex> factoryLock(_factoryMtx);
         // something that we don't recognize
         auto uq = std::make_shared<UserQueryInvalid>("Invalid or unsupported query: " + query);
         return uq;
diff --git a/src/ccontrol/UserQueryFactory.h b/src/ccontrol/UserQueryFactory.h
index a467ea07a..a62575a26 100644
--- a/src/ccontrol/UserQueryFactory.h
+++ b/src/ccontrol/UserQueryFactory.h
@@ -103,6 +103,10 @@ class UserQueryFactory : private boost::noncopyable {
     boost::asio::io_service _asioIoService;
     std::unique_ptr<boost::asio::io_service::work> _asioWork;
     std::unique_ptr<std::thread> _asioTimerThread;
+
+    /// Protects CSS in `qs->analyzeQuery(query, stmt);` and
+    /// protects uq calls that alter the database.
+    std::mutex _factoryMtx;
 };
 
 }  // namespace lsst::qserv::ccontrol
diff --git a/src/czar/Czar.cc b/src/czar/Czar.cc
index bf44d539b..340922620 100644
--- a/src/czar/Czar.cc
+++ b/src/czar/Czar.cc
@@ -224,12 +224,8 @@ SubmitResult Czar::submitQuery(string const& query, map<string, string> const& h
 
     // make new UserQuery
     // this is atomic
-    ccontrol::UserQuery::Ptr uq;
-    {
-        lock_guard<mutex> lock(_mutex);
-        uq = _uqFactory->newUserQuery(query, defaultDb, getQdispSharedResources(), userQueryId, msgTableName,
-                                      resultDb);
-    }
+    ccontrol::UserQuery::Ptr uq = _uqFactory->newUserQuery(query, defaultDb, getQdispSharedResources(),
+                                                           userQueryId, msgTableName, resultDb);
 
     // Add logging context with query ID
     QSERV_LOGCONTEXT_QUERY(uq->getQueryId());