diff --git a/src/core/CsvParser.cpp b/src/core/CsvParser.cpp
index e545d1db4..7e4929481 100644
--- a/src/core/CsvParser.cpp
+++ b/src/core/CsvParser.cpp
@@ -403,10 +403,11 @@ QString CsvParser::getStatus() const
 
 int CsvParser::getCsvCols() const
 {
-    if ((m_table.size() > 0) && (m_table.at(0).size() > 0))
+    if (!m_table.isEmpty() && !m_table.at(0).isEmpty()) {
         return m_table.at(0).size();
-    else
+    } else {
         return 0;
+    }
 }
 
 int CsvParser::getCsvRows() const
diff --git a/src/format/KdbxXmlReader.cpp b/src/format/KdbxXmlReader.cpp
index 163a9fa9d..efef724d9 100644
--- a/src/format/KdbxXmlReader.cpp
+++ b/src/format/KdbxXmlReader.cpp
@@ -731,7 +731,7 @@ Entry* KdbxXmlReader::parseEntry(bool history)
         }
         if (m_xml.name() == "Binary") {
             QPair<QString, QString> ref = parseEntryBinary(entry);
-            if (!ref.first.isNull() && !ref.second.isNull()) {
+            if (!ref.first.isEmpty() && !ref.second.isEmpty()) {
                 binaryRefs.append(ref);
             }
             continue;
diff --git a/src/gui/DatabaseOpenWidget.cpp b/src/gui/DatabaseOpenWidget.cpp
index 9c496aa31..0983ad855 100644
--- a/src/gui/DatabaseOpenWidget.cpp
+++ b/src/gui/DatabaseOpenWidget.cpp
@@ -174,7 +174,7 @@ QSharedPointer<Database> DatabaseOpenWidget::database()
 
 void DatabaseOpenWidget::enterKey(const QString& pw, const QString& keyFile)
 {
-    if (!pw.isNull()) {
+    if (!pw.isEmpty()) {
         m_ui->editPassword->setText(pw);
     }
     if (!keyFile.isEmpty()) {
diff --git a/src/gui/EntryPreviewWidget.cpp b/src/gui/EntryPreviewWidget.cpp
index 7c88d1fa5..359360879 100644
--- a/src/gui/EntryPreviewWidget.cpp
+++ b/src/gui/EntryPreviewWidget.cpp
@@ -220,7 +220,7 @@ void EntryPreviewWidget::updateEntryAttributesTab()
     m_ui->entryAttributesEdit->clear();
     const EntryAttributes* attributes = m_currentEntry->attributes();
     const QStringList customAttributes = attributes->customKeys();
-    const bool haveAttributes = customAttributes.size() > 0;
+    const bool haveAttributes = !customAttributes.isEmpty();
     setTabEnabled(m_ui->entryTabWidget, m_ui->entryAttributesTab, haveAttributes);
     if (haveAttributes) {
         QString attributesText;
diff --git a/tests/TestKeePass1Reader.cpp b/tests/TestKeePass1Reader.cpp
index bb9e07a42..078447acb 100644
--- a/tests/TestKeePass1Reader.cpp
+++ b/tests/TestKeePass1Reader.cpp
@@ -267,7 +267,7 @@ void TestKeePass1Reader::reopenDatabase(QSharedPointer<Database> db,
     QVERIFY(buffer.seek(0));
 
     auto key = QSharedPointer<CompositeKey>::create();
-    if (!password.isNull()) {
+    if (!password.isEmpty()) {
         key->addKey(QSharedPointer<PasswordKey>::create(password));
     }
     if (!keyfileName.isEmpty()) {
diff --git a/tests/TestKeys.cpp b/tests/TestKeys.cpp
index c2e9aa196..d25a2bca8 100644
--- a/tests/TestKeys.cpp
+++ b/tests/TestKeys.cpp
@@ -227,7 +227,7 @@ void TestKeys::testCompositeKeyComponents()
     auto fileKeyEnc = QSharedPointer<FileKey>::create();
     QString error;
     fileKeyEnc->load(QString("%1/%2").arg(QString(KEEPASSX_TEST_DATA_DIR), "FileKeyHashed.key"), &error);
-    if (!error.isNull()) {
+    if (!error.isEmpty()) {
         QFAIL(qPrintable(error));
     }
     auto challengeResponseKeyEnc = QSharedPointer<MockChallengeResponseKey>::create(QByteArray(16, 0x10));
@@ -285,7 +285,7 @@ void TestKeys::testCompositeKeyComponents()
     compositeKeyDec3->addKey(passwordKeyEnc);
     auto fileKeyWrong = QSharedPointer<FileKey>::create();
     fileKeyWrong->load(QString("%1/%2").arg(QString(KEEPASSX_TEST_DATA_DIR), "FileKeyHashed2.key"), &error);
-    if (!error.isNull()) {
+    if (!error.isEmpty()) {
         QFAIL(qPrintable(error));
     }
     compositeKeyDec3->addKey(fileKeyWrong);