diff --git a/src/num_builtin.h b/src/num_builtin.h
deleted file mode 100644
index a77e5ff..0000000
--- a/src/num_builtin.h
+++ /dev/null
@@ -1,155 +0,0 @@
-#ifndef _SECP256K1_NUM_GMP_
-#define _SECP256K1_NUM_GMP_
-
-#include <assert.h>
-#include <string>
-#include <string.h>
-#include <stdlib.h>
-
-namespace secp256k1 {
-
-class Number {
-private:
-    uint64_t n[8]; // 512 bits ought to be enough for everyone
-    int top; // number of used entries in n
-
-    void FixTop() {
-        while (top > 0 && n[top-1] == 0)
-            top--;
-    }
-
-    int GetNumBytes() {
-        if (top==0)
-            return 0;
-        int ret = 8*(top-1);
-        uint64_t h = n[top-1];
-        while (h>0) {
-            ret++;
-            h >>= 8;
-        }
-        return ret;
-    }
-
-    Number(const Number &c) {}
-public:
-    Number() {
-        top = 0;
-    }
-    Number(const unsigned char *bin, int len) {
-        top = 0;
-        SetBytes(bin, len);
-    }
-    Number &operator=(const Number &x) {
-        for (int pos = 0; pos < x.top; pos++)
-            n[pos] = x.n[pos];
-        top = x.top;
-    }
-    void SetNumber(const Number &x) {
-        *this = x;
-    }
-    void SetBytes(const unsigned char *bin, unsigned int len) {
-        n[0] = n[1] = n[2] = n[3] = n[4] = n[5] = n[6] = n[7] = 0;
-        assert(len<=64);
-        for (int pos = 0; pos < len; pos++)
-            n[(len-1-pos)/8] |= ((uint64_t)(bin[pos])) << (((len-1-pos)%8)*8);
-        top = 8;
-        FixTop();
-    }
-
-    void GetBytes(unsigned char *bin, unsigned int len) {
-        unsigned int size = GetNumBytes();
-        assert(size <= len);
-        memset(bin,0,len);
-        for (int i=0; i<size; i++)
-            bin[i] = (n[(size-i-1)/8] >> (((size-1-i)%8)*8)) & 0xFF;
-    }
-
-    void SetInt(int x) {
-        n[0] = x;
-        top = 1;
-        FixTop();
-    }
-
-    void SetModInverse(const Number &x, const Number &m) {
-        mpz_invert(bn, x.bn, m.bn);
-    }
-
-    void SetModMul(const Number &a, const Number &b, const Number &m) {
-        mpz_mul(bn, a.bn, b.bn);
-        mpz_mod(bn, bn, m.bn);
-    }
-    void SetAdd(const Number &a1, const Number &a2) {
-        
-        mpz_add(bn, a1.bn, a2.bn);
-    }
-    void SetSub(const Number &a1, const Number &a2) {
-        mpz_sub(bn, a1.bn, a2.bn);
-    }
-    void SetMult(const Number &a1, const Number &a2) {
-        mpz_mul(bn, a1.bn, a2.bn);
-    }
-    void SetDiv(const Number &a1, const Number &a2) {
-        mpz_tdiv_q(bn, a1.bn, a2.bn);
-    }
-    void SetMod(const Number &a, const Number &m) {
-        mpz_mod(bn, a.bn, m.bn);
-    }
-    int Compare(const Number &a) const {
-        return mpz_cmp(bn, a.bn);
-    }
-    int GetBits() const {
-        return mpz_sizeinbase(bn,2);
-    }
-    // return the lowest (rightmost) bits bits, and rshift them away
-    int ShiftLowBits(int bits) {
-        int ret = mpz_get_ui(bn) & ((1 << bits) - 1);
-        mpz_fdiv_q_2exp(bn, bn, bits);
-        return ret;
-    }
-    // check whether number is 0,
-    bool IsZero() const {
-        return mpz_size(bn) == 0;
-    }
-    bool IsOdd() const {
-        return mpz_get_ui(bn) & 1;
-    }
-    bool IsNeg() const {
-        return mpz_sgn(bn) < 0;
-    }
-    void Negate() {
-        mpz_neg(bn, bn);
-    }
-    void Shift1() {
-        mpz_fdiv_q_2exp(bn, bn, 1);
-    }
-    void Inc() {
-        mpz_add_ui(bn, bn, 1);
-    }
-    void SetHex(const std::string &str) {
-        mpz_set_str(bn, str.c_str(), 16);
-    }
-    void SetPseudoRand(const Number &max) {
-        number_state.gen(bn, max.bn);
-    }
-    void SplitInto(int bits, Number &low, Number &high) const {
-        mpz_t tmp;
-        mpz_init_set_ui(tmp,1);
-        mpz_mul_2exp(tmp,tmp,bits);
-        mpz_sub_ui(tmp,tmp,1);
-        mpz_and(low.bn, bn, tmp);
-        mpz_clear(tmp);
-        mpz_fdiv_q_2exp(high.bn, bn, bits);
-    }
-
-    std::string ToString() const {
-        char *str = (char*)malloc(mpz_sizeinbase(bn,16) + 2);
-        mpz_get_str(str, 16, bn);
-        std::string ret(str);
-        free(str);
-        return ret;
-    }
-};
-
-}
-
-#endif