C++ can't implement default constructor

I have a class:

class Fraction {
    private:
        int x;
        int y;
    public:
    // Constructors
        Fraction(long x = 0, long y = 1);
        Fraction(const Fraction&)=default;//here is the problem
        virtual ~Fraction();
 };

And I'm trying to disable default C++ constructor for copy, to do my own. So, I declared it as a default. But, when I'm trying to implement it:

Fraction::Fraction(const Fraction&){}

Compiler throws some errors at me.

./src/Fraction.cpp:16:1: error: definition of explicitly-defaulted ‘Fraction::Fraction(const Fraction&)’ Fraction::Fraction(const Fraction&){ ^ In file included from ../src/Fraction.cpp:8:0: ../src/Fraction.h:22:2: error: ‘Fraction::Fraction(const Fraction&)’ explicitly defaulted here Fraction(const Fraction&)=default;

Is there any way to fix it? What I'm doing wrong, I found some articles about defaults, but nothing that can help me to fix these errors.