diff --git a/commands/imagelib/effects/kpEffectFlattenCommand.h b/commands/imagelib/effects/kpEffectFlattenCommand.h
--- a/commands/imagelib/effects/kpEffectFlattenCommand.h
+++ b/commands/imagelib/effects/kpEffectFlattenCommand.h
@@ -39,7 +39,7 @@
 class kpEffectFlattenCommand : public kpEffectCommandBase
 {
 public:
-    kpEffectFlattenCommand (const QColor &color1, const QColor &color2,
+    kpEffectFlattenCommand (QColor color1, QColor color2,
                             bool actOnSelection,
                             kpCommandEnvironment *environ);
     ~kpEffectFlattenCommand () override;
diff --git a/commands/imagelib/effects/kpEffectFlattenCommand.cpp b/commands/imagelib/effects/kpEffectFlattenCommand.cpp
--- a/commands/imagelib/effects/kpEffectFlattenCommand.cpp
+++ b/commands/imagelib/effects/kpEffectFlattenCommand.cpp
@@ -28,20 +28,21 @@
 
 #define DEBUG_KP_EFFECT_FLATTEN 0
 
+#include <utility>
 
 #include "kpEffectFlattenCommand.h"
 #include "imagelib/effects/kpEffectFlatten.h"
 
 #include <KLocalizedString>
 
 //--------------------------------------------------------------------------------
 
-kpEffectFlattenCommand::kpEffectFlattenCommand (const QColor &color1,
-        const QColor &color2,
+kpEffectFlattenCommand::kpEffectFlattenCommand (QColor color1,
+        QColor color2,
         bool actOnSelection,
         kpCommandEnvironment *environ)
     : kpEffectCommandBase (i18n ("Flatten"), actOnSelection, environ),
-      m_color1 (color1), m_color2 (color2)
+      m_color1 (std::move(color1)), m_color2 (std::move(color2))
 {
 }
 
diff --git a/commands/kpNamedCommand.h b/commands/kpNamedCommand.h
--- a/commands/kpNamedCommand.h
+++ b/commands/kpNamedCommand.h
@@ -38,7 +38,7 @@
 class kpNamedCommand : public kpCommand
 {
 public:
-    kpNamedCommand (const QString &name, kpCommandEnvironment *environ);
+    kpNamedCommand (QString name, kpCommandEnvironment *environ);
 
     QString name () const override;
 
diff --git a/commands/kpNamedCommand.cpp b/commands/kpNamedCommand.cpp
--- a/commands/kpNamedCommand.cpp
+++ b/commands/kpNamedCommand.cpp
@@ -24,13 +24,15 @@
    THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
+#include <utility>
+
 #include "commands/kpNamedCommand.h"
 
 //---------------------------------------------------------------------
 
-kpNamedCommand::kpNamedCommand (const QString &name, kpCommandEnvironment *environ)
+kpNamedCommand::kpNamedCommand (QString name, kpCommandEnvironment *environ)
     : kpCommand (environ),
-      m_name (name)
+      m_name (std::move(name))
 {
 }
 
diff --git a/dialogs/imagelib/transforms/kpTransformPreviewDialog.h b/dialogs/imagelib/transforms/kpTransformPreviewDialog.h
--- a/dialogs/imagelib/transforms/kpTransformPreviewDialog.h
+++ b/dialogs/imagelib/transforms/kpTransformPreviewDialog.h
@@ -61,7 +61,7 @@
         // e.g. "Skew (Image|Selection)"
         const QString &caption,
         // (in the Dimensions Group Box) e.g. "After Skew:"
-        const QString &afterActionText,
+        QString afterActionText,
         bool actOnSelection,
         kpTransformDialogEnvironment *_env,
         QWidget *parent);
diff --git a/dialogs/imagelib/transforms/kpTransformPreviewDialog.cpp b/dialogs/imagelib/transforms/kpTransformPreviewDialog.cpp
--- a/dialogs/imagelib/transforms/kpTransformPreviewDialog.cpp
+++ b/dialogs/imagelib/transforms/kpTransformPreviewDialog.cpp
@@ -1,3 +1,5 @@
+#include <utility>
+
 
 /*
    Copyright (c) 2003-2007 Clarence Dang <dang@kde.org>
@@ -55,12 +57,12 @@
 kpTransformPreviewDialog::kpTransformPreviewDialog (Features features,
         bool reserveTopRow,
         const QString &caption,
-        const QString &afterActionText,
+        QString afterActionText,
         bool actOnSelection,
         kpTransformDialogEnvironment *_env,
         QWidget *parent)
     : QDialog (parent),
-      m_afterActionText (afterActionText),
+      m_afterActionText (std::move(afterActionText)),
       m_actOnSelection (actOnSelection),
       m_dimensionsGroupBox (nullptr),
       m_afterTransformDimensionsLabel (nullptr),
diff --git a/document/kpDocumentSaveOptions.cpp b/document/kpDocumentSaveOptions.cpp
--- a/document/kpDocumentSaveOptions.cpp
+++ b/document/kpDocumentSaveOptions.cpp
@@ -1,3 +1,5 @@
+#include <utility>
+
 
 /*
    Copyright (c) 2003-2007 Clarence Dang <dang@kde.org>
@@ -79,7 +81,7 @@
 kpDocumentSaveOptions::kpDocumentSaveOptions (QString mimeType, int colorDepth, bool dither, int quality)
     : d (new kpDocumentSaveOptionsPrivate ())
 {
-    d->m_mimeType = mimeType;
+    d->m_mimeType = std::move(mimeType);
     d->m_colorDepth = colorDepth;
     d->m_dither = dither;
     d->m_quality = quality;
diff --git a/layers/selections/text/kpTextStyle.h b/layers/selections/text/kpTextStyle.h
--- a/layers/selections/text/kpTextStyle.h
+++ b/layers/selections/text/kpTextStyle.h
@@ -44,7 +44,7 @@
 {
 public:
     kpTextStyle ();
-    kpTextStyle (const QString &fontFamily,
+    kpTextStyle (QString fontFamily,
                  int fontSize,
                  bool isBold, bool isItalic,
                  bool isUnderline, bool isStrikeThru,
diff --git a/layers/selections/text/kpTextStyle.cpp b/layers/selections/text/kpTextStyle.cpp
--- a/layers/selections/text/kpTextStyle.cpp
+++ b/layers/selections/text/kpTextStyle.cpp
@@ -1,3 +1,5 @@
+#include <utility>
+
 
 /*
    Copyright (c) 2003-2007 Clarence Dang <dang@kde.org>
@@ -41,13 +43,13 @@
 {
 }
 
-kpTextStyle::kpTextStyle (const QString &fontFamily,
+kpTextStyle::kpTextStyle (QString fontFamily,
                           int fontSize,
                           bool isBold, bool isItalic,
                           bool isUnderline, bool isStrikeThru,
                           const kpColor &fcolor, const kpColor &bcolor,
                           bool isBackgroundOpaque)
-    : m_fontFamily (fontFamily),
+    : m_fontFamily (std::move(fontFamily)),
       m_fontSize (fontSize),
       m_isBold (isBold), m_isItalic (isItalic),
       m_isUnderline (isUnderline), m_isStrikeThru (isStrikeThru),