diff --git a/src/server/handler/fetchhelper.cpp b/src/server/handler/fetchhelper.cpp
--- a/src/server/handler/fetchhelper.cpp
+++ b/src/server/handler/fetchhelper.cpp
@@ -369,30 +369,30 @@
     }
     // build part query if needed
     BEGIN_TIMER(parts)
-    QSqlQuery partQuery;
+    QSqlQuery partQuery(DataStore::self()->database());
     if (!mFetchScope.requestedParts().isEmpty() || mFetchScope.fullPayload() || mFetchScope.allAttributes()) {
         partQuery = buildPartQuery(mFetchScope.requestedParts(), mFetchScope.fullPayload(), mFetchScope.allAttributes());
     }
     END_TIMER(parts)
 
     // build flag query if needed
     BEGIN_TIMER(flags)
-    QSqlQuery flagQuery;
+    QSqlQuery flagQuery(DataStore::self()->database());
     if (mFetchScope.fetchFlags()) {
         flagQuery = buildFlagQuery();
     }
     END_TIMER(flags)
 
     // build tag query if needed
     BEGIN_TIMER(tags)
-    QSqlQuery tagQuery;
+    QSqlQuery tagQuery(DataStore::self()->database());
     if (mFetchScope.fetchTags()) {
         tagQuery = buildTagQuery();
     }
     END_TIMER(tags)
 
     BEGIN_TIMER(vRefs)
-    QSqlQuery vRefQuery;
+    QSqlQuery vRefQuery(DataStore::self()->database());
     if (mFetchScope.fetchVirtualReferences()) {
         vRefQuery = buildVRefQuery();
     }
diff --git a/src/server/handler/list.cpp b/src/server/handler/list.cpp
--- a/src/server/handler/list.cpp
+++ b/src/server/handler/list.cpp
@@ -445,8 +445,8 @@
     const int querySizeLimit = 999;
     int mimetypeQueryStart = 0;
     int attributeQueryStart = 0;
-    QSqlQuery mimeTypeQuery;
-    QSqlQuery attributeQuery;
+    QSqlQuery mimeTypeQuery(DataStore::self()->database());
+    QSqlQuery attributeQuery(DataStore::self()->database());
     auto it = mCollections.begin();
     while (it != mCollections.end()) {
         const Collection col = it.value();
diff --git a/src/server/storage/querybuilder.cpp b/src/server/storage/querybuilder.cpp
--- a/src/server/storage/querybuilder.cpp
+++ b/src/server/storage/querybuilder.cpp
@@ -101,6 +101,7 @@
     : mTable(table)
 #ifndef QUERYBUILDER_UNITTEST
     , mDatabaseType(DbType::type(DataStore::self()->database()))
+    , mQuery(DataStore::self()->database())
 #else
     , mDatabaseType(DbType::Unknown)
 #endif
@@ -356,7 +357,7 @@
     if (QueryCache::contains(statement)) {
         mQuery = QueryCache::query(statement);
     } else {
-        mQuery = QSqlQuery(DataStore::self()->database());
+        mQuery.clear();
         mQuery.prepare(statement);
         QueryCache::insert(statement, mQuery);
     }