diff --git a/lib/crypto/bn.js b/lib/crypto/bn.js
index 1625d32..1eb8c2a 100644
--- a/lib/crypto/bn.js
+++ b/lib/crypto/bn.js
@@ -19,16 +19,6 @@ var reversebuf = function(buf) {
   return buf2;
 };
 
-BN.prototype.toJSON = function() {
-  return this.toString();
-};
-
-BN.prototype.fromJSON = function(str) {
-  var bn = BN(str);
-  bn.copy(this);
-  return this;
-};
-
 BN.prototype.fromNumber = function(n) {
   var bn = BN(n);
   bn.copy(this);
diff --git a/test/crypto/bn.js b/test/crypto/bn.js
index 298c8d4..a771ae0 100644
--- a/test/crypto/bn.js
+++ b/test/crypto/bn.js
@@ -67,23 +67,6 @@ describe('BN', function() {
 
   });
 
-  describe('#fromJSON', function() {
-    
-    it('should make BN from a string', function() {
-      BN().fromJSON('5').toString().should.equal('5');
-    });
-
-  });
-
-  describe('#toJSON', function() {
-    
-    it('should make string from a BN', function() {
-      BN(5).toJSON().should.equal('5');
-      BN().fromJSON('5').toJSON().should.equal('5');
-    });
-
-  });
-
   describe('#fromString', function() {
     
     it('should make BN from a string', function() {