Index: b/lang/qt/tests/Makefile.am
===================================================================
--- b/lang/qt/tests/Makefile.am
+++ b/lang/qt/tests/Makefile.am
@@ -25,10 +25,11 @@
 EXTRA_DIST = initial.test
 
 TESTS = initial.test t-keylist t-keylocate t-ownertrust t-tofuinfo \
-        t-encrypt t-verify
+        t-encrypt t-verify t-config
 
 moc_files = t-keylist.moc t-keylocate.moc t-ownertrust.moc t-tofuinfo.moc \
-            t-encrypt.moc t-support.hmoc t-wkspublish.moc t-verify.moc
+            t-encrypt.moc t-support.hmoc t-wkspublish.moc t-verify.moc \
+            t-config.moc
 
 AM_LDFLAGS = -no-install
 
@@ -57,6 +58,7 @@
 t_encrypt_SOURCES = t-encrypt.cpp $(support_src)
 t_wkspublish_SOURCES = t-wkspublish.cpp $(support_src)
 t_verify_SOURCES = t-verify.cpp $(support_src)
+t_config_SOURCES = t-config.cpp $(support_src)
 run_keyformailboxjob_SOURCES = run-keyformailboxjob.cpp
 
 nodist_t_keylist_SOURCES = $(moc_files)
@@ -64,7 +66,7 @@
 BUILT_SOURCES = $(moc_files)
 
 noinst_PROGRAMS = t-keylist t-keylocate t-ownertrust t-tofuinfo t-encrypt \
-    run-keyformailboxjob t-wkspublish t-verify
+    run-keyformailboxjob t-wkspublish t-verify t-config
 
 CLEANFILES = secring.gpg pubring.gpg pubring.kbx trustdb.gpg dirmngr.conf \
 	gpg-agent.conf pubring.kbx~ S.gpg-agent gpg.conf pubring.gpg~ \
Index: b/lang/qt/tests/t-config.cpp
===================================================================
--- /dev/null
+++ b/lang/qt/tests/t-config.cpp
@@ -0,0 +1,92 @@
+/* t-config.cpp
+
+    This file is part of qgpgme, the Qt API binding for gpgme
+    Copyright (c) 2016 Intevation GmbH
+
+    QGpgME is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.
+
+    QGpgME is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of this program with any edition of
+    the Qt library by Trolltech AS, Norway (or with modified versions
+    of Qt that use the same license as Qt), and distribute linked
+    combinations including the two.  You must obey the GNU General
+    Public License in all respects for all of the code used other than
+    Qt.  If you modify this file, you may extend this exception to
+    your version of the file, but you are not obligated to do so.  If
+    you do not wish to do so, delete this exception statement from
+    your version.
+*/
+#ifdef HAVE_CONFIG_H
+ #include "config.h"
+#endif
+
+#include <QDebug>
+#include <QTest>
+#include <QTemporaryDir>
+#include "t-support.h"
+#include "protocol.h"
+#include "cryptoconfig.h"
+#include <unistd.h>
+
+using namespace QGpgME;
+
+class CryptoConfigTest: public QGpgMETest
+{
+    Q_OBJECT
+
+private Q_SLOTS:
+    void testKeyserver()
+    {
+        for (int i = 0; i < 100; i++) {
+            qDebug() << "Loop: " << i;
+            auto conf = cryptoConfig();
+            Q_ASSERT (conf);
+            auto entry = conf->entry(QStringLiteral("gpg"),
+                    QStringLiteral("Keyserver"),
+                    QStringLiteral("keyserver"));
+            Q_ASSERT(entry);
+            const QString url(QStringLiteral("hkp://foo.bar.baz"));
+            entry->setStringValue(url);
+            conf->sync(false);
+            conf->clear();
+            entry = conf->entry(QStringLiteral("gpg"),
+                    QStringLiteral("Keyserver"),
+                    QStringLiteral("keyserver"));
+            QCOMPARE (entry->stringValue(), url);
+            entry->setStringValue(QString());
+            conf->sync(false);
+            conf->clear();
+            entry = conf->entry(QStringLiteral("gpg"),
+                    QStringLiteral("Keyserver"),
+                    QStringLiteral("keyserver"));
+            QCOMPARE (entry->stringValue(), QString());
+        }
+    }
+
+    void initTestCase()
+    {
+        QGpgMETest::initTestCase();
+        const QString gpgHome = qgetenv("GNUPGHOME");
+        qputenv("GNUPGHOME", mDir.path().toUtf8());
+        Q_ASSERT(mDir.isValid());
+    }
+private:
+    QTemporaryDir mDir;
+
+};
+
+QTEST_MAIN(CryptoConfigTest)
+
+#include "t-config.moc"