diff --git a/common/src/main/java/com/linecorp/line/auth/fido/fido2/common/COSEAlgorithmIdentifier.java b/common/src/main/java/com/linecorp/line/auth/fido/fido2/common/COSEAlgorithmIdentifier.java
index f470f4c..9b65bbf 100644
--- a/common/src/main/java/com/linecorp/line/auth/fido/fido2/common/COSEAlgorithmIdentifier.java
+++ b/common/src/main/java/com/linecorp/line/auth/fido/fido2/common/COSEAlgorithmIdentifier.java
@@ -37,7 +37,7 @@ public enum COSEAlgorithmIdentifier {
     ES384(-35),
     ES512(-36),
     EdDSA(-8),
-    ES256K(-43);
+    ES256K(-47);
 
     @JsonValue
     @Getter private final long value;
diff --git a/common/src/main/java/com/linecorp/line/auth/fido/fido2/common/server/COSEAlgorithm.java b/common/src/main/java/com/linecorp/line/auth/fido/fido2/common/server/COSEAlgorithm.java
index 18d44b6..a811114 100644
--- a/common/src/main/java/com/linecorp/line/auth/fido/fido2/common/server/COSEAlgorithm.java
+++ b/common/src/main/java/com/linecorp/line/auth/fido/fido2/common/server/COSEAlgorithm.java
@@ -35,7 +35,7 @@ public enum COSEAlgorithm {
     ES256("ES256", -7, "ECDSA w/ SHA-256", true),
     ES384("ES384", -35, "ECDSA w/ SHA-384", true),
     ES512("ES512", -36, "ECDSA w/ SHA-512", true),
-    ES256K("ES256K", -43, "ECDSA using P-256K and SHA-256", false);
+    ES256K("ES256K", -47, "ECDSA using P-256K and SHA-256", false);
 
     private final String name;
     private final int value;
diff --git a/server/src/test/resources/json/reg/reg-challenge-res.json b/server/src/test/resources/json/reg/reg-challenge-res.json
index 7f8b0e3..9b863ac 100644
--- a/server/src/test/resources/json/reg/reg-challenge-res.json
+++ b/server/src/test/resources/json/reg/reg-challenge-res.json
@@ -64,7 +64,7 @@
     },
     {
       "type": "public-key",
-      "alg": -43
+      "alg": -47
     }
   ],
   "timeout": 180000,