diff --git a/include/mapnik/gradient.hpp b/include/mapnik/gradient.hpp
index 0f7f838a8..37d44a28a 100644
--- a/include/mapnik/gradient.hpp
+++ b/include/mapnik/gradient.hpp
@@ -77,15 +77,15 @@ class MAPNIK_DECL gradient
     // transform
     agg::trans_affine transform_;
 public:
-    explicit gradient();
+    gradient();
     gradient(gradient const& other);
     gradient& operator=(const gradient& rhs);
 
     void set_gradient_type(gradient_e grad);
     gradient_e get_gradient_type() const;
 
-    void set_transform(agg::trans_affine transform);
-    agg::trans_affine get_transform() const;
+    void set_transform(agg::trans_affine const& transform);
+    agg::trans_affine const&  get_transform() const;
 
     void set_units(gradient_unit_e units);
     gradient_unit_e get_units() const;
diff --git a/src/gradient.cpp b/src/gradient.cpp
index 3d4771c0f..28452b8da 100644
--- a/src/gradient.cpp
+++ b/src/gradient.cpp
@@ -44,9 +44,9 @@ gradient::gradient()
     x2_(0),
     y2_(0),
     r_(0),
-    units_(OBJECT_BOUNDING_BOX)
-{
-}
+    units_(OBJECT_BOUNDING_BOX),
+    transform_()
+{}
 
 gradient::gradient(gradient const& other)
     : gradient_type_(other.gradient_type_),
@@ -77,11 +77,11 @@ gradient_e gradient::get_gradient_type() const
     return gradient_type_;
 }
 
-void gradient::set_transform(agg::trans_affine transform)
+void gradient::set_transform(agg::trans_affine const& transform)
 {
     transform_ = transform;
 }
-agg::trans_affine gradient::get_transform() const
+agg::trans_affine const& gradient::get_transform() const
 {
     return transform_;
 }