diff --git a/jose/backends/cryptography_backend.py b/jose/backends/cryptography_backend.py
index b9bdc0dc..59940a21 100644
--- a/jose/backends/cryptography_backend.py
+++ b/jose/backends/cryptography_backend.py
@@ -36,7 +36,8 @@ def __init__(self, key, algorithm, cryptography_backend=default_backend):
         self.hash_alg = {
             ALGORITHMS.ES256: self.SHA256,
             ALGORITHMS.ES384: self.SHA384,
-            ALGORITHMS.ES512: self.SHA512
+            ALGORITHMS.ES512: self.SHA512,
+            ALGORITHMS.ES256K: self.SHA256
         }.get(algorithm)
         self._algorithm = algorithm
 
@@ -87,6 +88,7 @@ def _process_jwk(self, jwk_dict):
             'P-256': ec.SECP256R1,
             'P-384': ec.SECP384R1,
             'P-521': ec.SECP521R1,
+            'P-256K': ec.SECP256K1,
         }[jwk_dict['crv']]
 
         public = ec.EllipticCurvePublicNumbers(x, y, curve())
@@ -172,6 +174,7 @@ def to_dict(self):
             'secp256r1': 'P-256',
             'secp384r1': 'P-384',
             'secp521r1': 'P-521',
+            'secp256k1': 'P-256K',
         }[self.prepared_key.curve.name]
 
         # Calculate the key size in bytes. Section 6.2.1.2 and 6.2.1.3 of
diff --git a/jose/backends/ecdsa_backend.py b/jose/backends/ecdsa_backend.py
index 8b8b9a23..0266a75b 100644
--- a/jose/backends/ecdsa_backend.py
+++ b/jose/backends/ecdsa_backend.py
@@ -26,6 +26,7 @@ class ECDSAECKey(Key):
         SHA256: ecdsa.curves.NIST256p,
         SHA384: ecdsa.curves.NIST384p,
         SHA512: ecdsa.curves.NIST521p,
+        SHA256: ecdsa.curves.SECP256k1,
     }
 
     def __init__(self, key, algorithm):
@@ -35,7 +36,8 @@ def __init__(self, key, algorithm):
         self.hash_alg = {
             ALGORITHMS.ES256: self.SHA256,
             ALGORITHMS.ES384: self.SHA384,
-            ALGORITHMS.ES512: self.SHA512
+            ALGORITHMS.ES512: self.SHA512,
+            ALGORITHMS.ES256K: self.SHA256
         }.get(algorithm)
         self._algorithm = algorithm
 
@@ -120,6 +122,7 @@ def to_dict(self):
             ecdsa.curves.NIST256p: 'P-256',
             ecdsa.curves.NIST384p: 'P-384',
             ecdsa.curves.NIST521p: 'P-521',
+            ecdsa.curves.SECP256k1: 'P-256K',
         }[self.prepared_key.curve]
 
         # Calculate the key size in bytes. Section 6.2.1.2 and 6.2.1.3 of
diff --git a/jose/constants.py b/jose/constants.py
index eb146549..24766dfa 100644
--- a/jose/constants.py
+++ b/jose/constants.py
@@ -12,10 +12,11 @@ class Algorithms(object):
     ES256 = 'ES256'
     ES384 = 'ES384'
     ES512 = 'ES512'
+    ES256K = 'ES256K'
 
     HMAC = {HS256, HS384, HS512}
     RSA = {RS256, RS384, RS512}
-    EC = {ES256, ES384, ES512}
+    EC = {ES256, ES384, ES512, ES256K}
 
     SUPPORTED = HMAC.union(RSA).union(EC)
 
@@ -31,6 +32,7 @@ class Algorithms(object):
         ES256: hashlib.sha256,
         ES384: hashlib.sha384,
         ES512: hashlib.sha512,
+        ES256K: hashlib.sha256,
     }
 
     KEYS = {}
diff --git a/jose/jwk.py b/jose/jwk.py
index 87f30b41..2db20025 100644
--- a/jose/jwk.py
+++ b/jose/jwk.py
@@ -72,6 +72,7 @@ def get_algorithm_object(algorithm):
         ALGORITHMS.ES256: 'SHA256',
         ALGORITHMS.ES384: 'SHA384',
         ALGORITHMS.ES512: 'SHA512',
+        ALGORITHMS.ES256K: 'SHA256',
     }
     key = get_key(algorithm)
     attr = algorithms.get(algorithm, None)
diff --git a/tests/test_jws.py b/tests/test_jws.py
index f543a03a..e6aa05b3 100644
--- a/tests/test_jws.py
+++ b/tests/test_jws.py
@@ -322,6 +322,10 @@ def test_EC512(self, payload):
         token = jws.sign(payload, ec_private_key, algorithm=ALGORITHMS.ES512)
         assert jws.verify(token, ec_public_key, ALGORITHMS.ES512) == payload
 
+    def test_EC256K(self, payload):
+        token = jws.sign(payload, ec_private_key, algorithm=ALGORITHMS.ES256K)
+        assert jws.verify(token, ec_public_key, ALGORITHMS.ES256K) == payload
+
     def test_wrong_alg(self, payload):
         token = jws.sign(payload, ec_private_key, algorithm=ALGORITHMS.ES256)
         with pytest.raises(JWSError):