diff --git a/src/Math/Vector3.h b/src/Math/Vector3.h
index be9934043..5653ca6de 100644
--- a/src/Math/Vector3.h
+++ b/src/Math/Vector3.h
@@ -68,7 +68,7 @@ template<class T> class Vector3: public Vector<3, T> {
          * @param other     Two component vector
          * @param z         Z / B value
          */
-        inline constexpr Vector3(const Vector<2, T>& other, T z = T(0)): Vector<3, T>(other[0], other[1], z) {}
+        inline constexpr Vector3(const Vector<2, T>& other, T z): Vector<3, T>(other[0], other[1], z) {}
 
         inline constexpr T x() const { return (*this)[0]; } /**< @brief X component */
         inline constexpr T y() const { return (*this)[1]; } /**< @brief Y component */
diff --git a/src/Math/Vector4.h b/src/Math/Vector4.h
index 5b1e57418..2661f8344 100644
--- a/src/Math/Vector4.h
+++ b/src/Math/Vector4.h
@@ -53,6 +53,8 @@ template<class T> class Vector4: public Vector<4, T> {
          * @param other     Three component vector
          * @param w         W / A value
          */
+        /* Not marked as explicit, because conversion from Vector3 to Vector4
+           is fairly common, nearly always with W set to 1 */
         inline constexpr Vector4(const Vector<3, T>& other, T w = T(1)): Vector<4, T>(other[0], other[1], other[2], w) {}
 
         inline constexpr T x() const { return (*this)[0]; } /**< @brief X component */