diff --git a/src/imageformats/pcx.cpp b/src/imageformats/pcx.cpp
index ad12c85..a45ba96 100644
--- a/src/imageformats/pcx.cpp
+++ b/src/imageformats/pcx.cpp
@@ -23,7 +23,7 @@ public:
     quint8 g;
     quint8 b;
 
-    static RGB from(const QRgb &color)
+    static RGB from(const QRgb color)
     {
         RGB c;
         c.r = qRed(color);
@@ -169,7 +169,7 @@ static QDataStream &operator>>(QDataStream &s, PCXHEADER &ph)
     return s;
 }
 
-static QDataStream &operator<<(QDataStream &s, const RGB &rgb)
+static QDataStream &operator<<(QDataStream &s, const RGB rgb)
 {
     s << rgb.r << rgb.g << rgb.b;
 
diff --git a/src/imageformats/xcf.cpp b/src/imageformats/xcf.cpp
index 43a7d80..d92f5e9 100644
--- a/src/imageformats/xcf.cpp
+++ b/src/imageformats/xcf.cpp
@@ -276,7 +276,7 @@ const XCFImageFormat::LayerModes XCFImageFormat::layer_modes[] = {
 };
 
 //! Change a QRgb value's alpha only.
-inline QRgb qRgba(const QRgb &rgb, int a)
+inline QRgb qRgba(const QRgb rgb, int a)
 {
     return ((a & 0xff) << 24 | (rgb & RGB_MASK));
 }