diff --git a/src/backend/corebackenddevice.h b/src/backend/corebackenddevice.h
index 0629f33..79c0f85 100644
--- a/src/backend/corebackenddevice.h
+++ b/src/backend/corebackenddevice.h
@@ -39,7 +39,7 @@ class Report;
 class CoreBackendDevice
 {
 public:
-    CoreBackendDevice(const QString& deviceNode);
+    explicit CoreBackendDevice(const QString& deviceNode);
     virtual ~CoreBackendDevice() {}
 
 public:
diff --git a/src/core/copysourcefile.h b/src/core/copysourcefile.h
index 3a5cebd..458b161 100644
--- a/src/core/copysourcefile.h
+++ b/src/core/copysourcefile.h
@@ -36,7 +36,7 @@ class CopyTarget;
 class CopySourceFile : public CopySource
 {
 public:
-    CopySourceFile(const QString& filename);
+    explicit CopySourceFile(const QString& filename);
 
 public:
     bool open() override;
diff --git a/src/core/copytargetbytearray.h b/src/core/copytargetbytearray.h
index 709fa9a..4c4a38a 100644
--- a/src/core/copytargetbytearray.h
+++ b/src/core/copytargetbytearray.h
@@ -34,7 +34,7 @@
 class CopyTargetByteArray : public CopyTarget
 {
 public:
-    CopyTargetByteArray(QByteArray& array);
+    explicit CopyTargetByteArray(QByteArray& array);
 
 public:
     bool open() override {
diff --git a/src/core/copytargetfile.h b/src/core/copytargetfile.h
index 258a403..53c32d7 100644
--- a/src/core/copytargetfile.h
+++ b/src/core/copytargetfile.h
@@ -36,7 +36,7 @@ class QString;
 class CopyTargetFile : public CopyTarget
 {
 public:
-    CopyTargetFile(const QString& filename);
+    explicit CopyTargetFile(const QString& filename);
 
 public:
     bool open() override;
diff --git a/src/core/lvmdevice.cpp b/src/core/lvmdevice.cpp
index 3ee126c..1df14e5 100644
--- a/src/core/lvmdevice.cpp
+++ b/src/core/lvmdevice.cpp
@@ -171,7 +171,7 @@ Partition* LvmDevice::scanPartition(const QString& lvPath, PartitionTable* pTabl
         mountPoint = FileSystem::detectMountPoint(fs, lvPath);
         mounted = FileSystem::detectMountStatus(fs, lvPath);
 
-        if (mountPoint != QString() && fs->type() != FileSystem::Type::LinuxSwap) {
+        if (!mountPoint.isEmpty() && fs->type() != FileSystem::Type::LinuxSwap) {
             const QStorageInfo storage = QStorageInfo(mountPoint);
             if (logicalSize() > 0 && fs->type() != FileSystem::Type::Luks && mounted && storage.isValid())
                 fs->setSectorsUsed( (storage.bytesTotal() - storage.bytesFree()) / logicalSize() );
diff --git a/src/core/lvmdevice.h b/src/core/lvmdevice.h
index 922ed01..16d1cc0 100644
--- a/src/core/lvmdevice.h
+++ b/src/core/lvmdevice.h
@@ -48,7 +48,7 @@ class LIBKPMCORE_EXPORT LvmDevice : public VolumeManagerDevice
     friend class VolumeManagerDevice;
 
 public:
-    LvmDevice(const QString& name, const QString& iconName = QString());
+    explicit LvmDevice(const QString& name, const QString& iconName = QString());
     ~LvmDevice();
 
 public:
diff --git a/src/core/operationstack.h b/src/core/operationstack.h
index ccf2897..7276dd4 100644
--- a/src/core/operationstack.h
+++ b/src/core/operationstack.h
@@ -51,7 +51,7 @@ public:
     typedef QList<Operation*> Operations;
 
 public:
-    OperationStack(QObject* parent = nullptr);
+    explicit OperationStack(QObject* parent = nullptr);
     ~OperationStack();
 
 Q_SIGNALS:
diff --git a/src/core/raid/softwareraid.h b/src/core/raid/softwareraid.h
index 447856b..0789ec2 100644
--- a/src/core/raid/softwareraid.h
+++ b/src/core/raid/softwareraid.h
@@ -36,7 +36,7 @@ public:
         Recovery,
     };
 
-    SoftwareRAID(const QString& name,
+    explicit SoftwareRAID(const QString& name,
                  SoftwareRAID::Status status = SoftwareRAID::Status::Active,
                  const QString& iconName = QString());
 
diff --git a/src/core/smartattribute.h b/src/core/smartattribute.h
index 2df9ae9..7df36a4 100644
--- a/src/core/smartattribute.h
+++ b/src/core/smartattribute.h
@@ -46,7 +46,7 @@ public:
     };
 
 public:
-    SmartAttribute(const SmartAttributeParsedData& a);
+    explicit SmartAttribute(const SmartAttributeParsedData& a);
 
 public:
     qint32 id() const {
diff --git a/src/core/smartparser.h b/src/core/smartparser.h
index 6869c01..115fbd5 100644
--- a/src/core/smartparser.h
+++ b/src/core/smartparser.h
@@ -32,7 +32,7 @@ class SmartDiskInformation;
 class SmartParser
 {
 public:
-    SmartParser(const QString &device_path);
+    explicit SmartParser(const QString &device_path);
     ~SmartParser();
 
 public:
diff --git a/src/core/smartstatus.h b/src/core/smartstatus.h
index 06defe8..d480cd2 100644
--- a/src/core/smartstatus.h
+++ b/src/core/smartstatus.h
@@ -57,7 +57,7 @@ public:
     typedef QList<SmartAttribute> Attributes;
 
 public:
-    SmartStatus(const QString &device_path);
+    explicit SmartStatus(const QString &device_path);
 
 public:
     void update();
diff --git a/src/core/volumemanagerdevice.cpp b/src/core/volumemanagerdevice.cpp
index 68036d1..3e87dc3 100644
--- a/src/core/volumemanagerdevice.cpp
+++ b/src/core/volumemanagerdevice.cpp
@@ -16,9 +16,9 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.*
  *************************************************************************/
 
-#include "core/device_p.h"
 #include "core/volumemanagerdevice.h"
 #include "core/volumemanagerdevice_p.h"
+#include "core/device_p.h"
 #include "core/lvmdevice.h"
 #include "core/raid/softwareraid.h"
 
diff --git a/src/fs/filesystem.cpp b/src/fs/filesystem.cpp
index 8b795f0..141c13d 100644
--- a/src/fs/filesystem.cpp
+++ b/src/fs/filesystem.cpp
@@ -17,9 +17,9 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.*
  *************************************************************************/
 
+#include "fs/filesystem.h"
 #include "core/fstab.h"
 
-#include "fs/filesystem.h"
 #include "fs/lvm2_pv.h"
 
 #include "backend/corebackend.h"
@@ -174,7 +174,7 @@ bool FileSystem::detectMountStatus(FileSystem* fs, const QString& partitionPath)
     bool mounted = false;
 
     if (fs->type() == FileSystem::Type::Lvm2_PV) {
-        mounted = FS::lvm2_pv::getVGName(partitionPath) != QString();
+        mounted = !FS::lvm2_pv::getVGName(partitionPath).isEmpty();
     } else {
         mounted = isMounted(partitionPath);
     }
diff --git a/src/gui/partresizerwidget.h b/src/gui/partresizerwidget.h
index dbbd57d..41d8e4a 100644
--- a/src/gui/partresizerwidget.h
+++ b/src/gui/partresizerwidget.h
@@ -45,7 +45,7 @@ class LIBKPMCORE_EXPORT PartResizerWidget : public QWidget
     Q_DISABLE_COPY(PartResizerWidget)
 
 public:
-    PartResizerWidget(QWidget* parent);
+    explicit PartResizerWidget(QWidget* parent);
 
 public:
     void init(Device& d, Partition& p, qint64 minFirst, qint64 maxLast, bool read_only = false, bool move_allowed = true);
diff --git a/src/jobs/checkfilesystemjob.h b/src/jobs/checkfilesystemjob.h
index 815d88d..e79e7f7 100644
--- a/src/jobs/checkfilesystemjob.h
+++ b/src/jobs/checkfilesystemjob.h
@@ -32,7 +32,7 @@ class QString;
 class CheckFileSystemJob : public Job
 {
 public:
-    CheckFileSystemJob(Partition& p);
+    explicit CheckFileSystemJob(Partition& p);
 
 public:
     bool run(Report& parent) override;
diff --git a/src/jobs/createpartitionjob.cpp b/src/jobs/createpartitionjob.cpp
index e6fb374..6f20ecd 100644
--- a/src/jobs/createpartitionjob.cpp
+++ b/src/jobs/createpartitionjob.cpp
@@ -59,7 +59,7 @@ bool CreatePartitionJob::run(Report& parent)
             if (backendPartitionTable) {
                 QString partitionPath = backendPartitionTable->createPartition(*report, partition());
 
-                if (partitionPath != QString()) {
+                if (!partitionPath.isEmpty()) {
                     rval = true;
                     partition().setPartitionPath(partitionPath);
                     partition().setState(Partition::State::None);
diff --git a/src/jobs/createpartitiontablejob.h b/src/jobs/createpartitiontablejob.h
index 0888b1a..de34ee5 100644
--- a/src/jobs/createpartitiontablejob.h
+++ b/src/jobs/createpartitiontablejob.h
@@ -32,7 +32,7 @@ class QString;
 class CreatePartitionTableJob : public Job
 {
 public:
-    CreatePartitionTableJob(Device& d);
+    explicit CreatePartitionTableJob(Device& d);
 
 public:
     bool run(Report& parent) override;
diff --git a/src/jobs/deactivatelogicalvolumejob.h b/src/jobs/deactivatelogicalvolumejob.h
index 8437977..e5d8da6 100644
--- a/src/jobs/deactivatelogicalvolumejob.h
+++ b/src/jobs/deactivatelogicalvolumejob.h
@@ -30,7 +30,7 @@ class QString;
 class DeactivateLogicalVolumeJob : public Job
 {
 public:
-    DeactivateLogicalVolumeJob(const VolumeManagerDevice& dev, const QStringList lvPaths = {});
+    explicit DeactivateLogicalVolumeJob(const VolumeManagerDevice& dev, const QStringList lvPaths = {});
 
 public:
     bool run(Report& parent) override;
diff --git a/src/jobs/deactivatevolumegroupjob.h b/src/jobs/deactivatevolumegroupjob.h
index a7886b9..308df1b 100644
--- a/src/jobs/deactivatevolumegroupjob.h
+++ b/src/jobs/deactivatevolumegroupjob.h
@@ -30,7 +30,7 @@ class QString;
 class DeactivateVolumeGroupJob : public Job
 {
 public:
-    DeactivateVolumeGroupJob(VolumeManagerDevice& dev);
+    explicit DeactivateVolumeGroupJob(VolumeManagerDevice& dev);
 
 public:
     bool run(Report& parent) override;
diff --git a/src/ops/deactivatevolumegroupoperation.h b/src/ops/deactivatevolumegroupoperation.h
index e0b2b00..bb4d722 100644
--- a/src/ops/deactivatevolumegroupoperation.h
+++ b/src/ops/deactivatevolumegroupoperation.h
@@ -39,7 +39,7 @@ class LIBKPMCORE_EXPORT DeactivateVolumeGroupOperation : public Operation
     friend class OperationStack;
 
 public:
-    DeactivateVolumeGroupOperation(VolumeManagerDevice& d);
+    explicit DeactivateVolumeGroupOperation(VolumeManagerDevice& d);
 
 public:
     QString iconName() const override {
diff --git a/src/ops/removevolumegroupoperation.h b/src/ops/removevolumegroupoperation.h
index 12e78a1..5bc8901 100644
--- a/src/ops/removevolumegroupoperation.h
+++ b/src/ops/removevolumegroupoperation.h
@@ -37,7 +37,7 @@ class LIBKPMCORE_EXPORT RemoveVolumeGroupOperation : public Operation
     friend class OperationStack;
 
 public:
-    RemoveVolumeGroupOperation(VolumeManagerDevice& d);
+    explicit RemoveVolumeGroupOperation(VolumeManagerDevice& d);
 
 public:
     QString iconName() const override {
diff --git a/src/plugins/dummy/dummydevice.h b/src/plugins/dummy/dummydevice.h
index 746c346..322a227 100644
--- a/src/plugins/dummy/dummydevice.h
+++ b/src/plugins/dummy/dummydevice.h
@@ -33,7 +33,7 @@ class DummyDevice : public CoreBackendDevice
     Q_DISABLE_COPY(DummyDevice)
 
 public:
-    DummyDevice(const QString& deviceNode);
+    explicit DummyDevice(const QString& deviceNode);
     ~DummyDevice();
 
 public:
diff --git a/src/plugins/sfdisk/sfdiskdevice.h b/src/plugins/sfdisk/sfdiskdevice.h
index eab4a12..ad83625 100644
--- a/src/plugins/sfdisk/sfdiskdevice.h
+++ b/src/plugins/sfdisk/sfdiskdevice.h
@@ -34,7 +34,7 @@ class SfdiskDevice : public CoreBackendDevice
     Q_DISABLE_COPY(SfdiskDevice);
 
 public:
-    SfdiskDevice(const Device& d);
+    explicit SfdiskDevice(const Device& d);
     ~SfdiskDevice();
 
 public:
diff --git a/src/plugins/sfdisk/sfdiskpartitiontable.h b/src/plugins/sfdisk/sfdiskpartitiontable.h
index 9d0de1e..577ab34 100644
--- a/src/plugins/sfdisk/sfdiskpartitiontable.h
+++ b/src/plugins/sfdisk/sfdiskpartitiontable.h
@@ -32,7 +32,7 @@ class Partition;
 class SfdiskPartitionTable : public CoreBackendPartitionTable
 {
 public:
-    SfdiskPartitionTable(const Device *d);
+    explicit SfdiskPartitionTable(const Device *d);
     ~SfdiskPartitionTable();
 
 public:
diff --git a/src/util/externalcommand.cpp b/src/util/externalcommand.cpp
index 0568bb6..9ba2fac 100644
--- a/src/util/externalcommand.cpp
+++ b/src/util/externalcommand.cpp
@@ -16,6 +16,7 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.*
  *************************************************************************/
 
+#include "util/externalcommand.h"
 #include "backend/corebackendmanager.h"
 #include "core/device.h"
 #include "core/copysource.h"
@@ -24,7 +25,6 @@
 #include "core/copysourcedevice.h"
 #include "core/copytargetdevice.h"
 #include "util/globallog.h"
-#include "util/externalcommand.h"
 #include "util/report.h"
 
 #include "externalcommandhelper_interface.h"
diff --git a/test/testdevice.cpp b/test/testdevice.cpp
index 43a424b..d74e1c3 100644
--- a/test/testdevice.cpp
+++ b/test/testdevice.cpp
@@ -17,8 +17,8 @@
  
  //  SPDX-License-Identifier: GPL-3.0+
 
-#include "helpers.h"
 #include "testdevice.h" 
+#include "helpers.h"
 
 #include "backend/corebackend.h"
 #include "backend/corebackendmanager.h"
@@ -81,7 +81,7 @@ void TestDevice::testDeviceName()
         exit(EXIT_FAILURE);
     } else {
         for (const auto &device : devices) {
-            if (device->name() == QString())
+            if (device->name().isEmpty())
                 exit(EXIT_FAILURE);
         }
     }