diff --git a/include/picotls.h b/include/picotls.h
index 6134467..a3050c1 100644
--- a/include/picotls.h
+++ b/include/picotls.h
@@ -124,6 +124,7 @@
 #define PTLS_SIGNATURE_RSA_PSS_RSAE_SHA256 0x0804
 #define PTLS_SIGNATURE_RSA_PSS_RSAE_SHA384 0x0805
 #define PTLS_SIGNATURE_RSA_PSS_RSAE_SHA512 0x0806
+#define PTLS_SIGNATURE_ED25519 0x0807
 
 /* ESNI */
 #define PTLS_ESNI_VERSION_DRAFT03 0xff02
diff --git a/lib/openssl.c b/lib/openssl.c
index 36344a9..4c5eaf0 100644
--- a/lib/openssl.c
+++ b/lib/openssl.c
@@ -102,6 +102,9 @@
 static const struct st_ptls_openssl_signature_scheme_t secp521r1_signature_schemes[] = {
     {PTLS_SIGNATURE_ECDSA_SECP521R1_SHA512, EVP_sha512}, {UINT16_MAX, NULL}};
 #endif
+#if defined EVP_PKEY_ED25519
+static const struct st_ptls_openssl_signature_scheme_t ed25519_signature_schemes[] = {{PTLS_SIGNATURE_ED25519, NULL}, {UINT16_MAX, NULL}};
+#endif
 
 /**
  * The default list sent in ClientHello.signature_algorithms. ECDSA certificates are preferred.
@@ -145,6 +148,11 @@
         }
         EC_KEY_free(eckey);
     } break;
+#if defined EVP_PKEY_ED25519
+    case EVP_PKEY_ED25519:
+        schemes = ed25519_signature_schemes;
+        break;
+#endif
     default:
         break;
     }
@@ -688,38 +696,61 @@
         ret = PTLS_ERROR_NO_MEMORY;
         goto Exit;
     }
+
     if (EVP_DigestSignInit(ctx, &pkey_ctx, md, NULL, key) != 1) {
         ret = PTLS_ERROR_LIBRARY;
         goto Exit;
     }
-    if (EVP_PKEY_id(key) == EVP_PKEY_RSA) {
-        if (EVP_PKEY_CTX_set_rsa_padding(pkey_ctx, RSA_PKCS1_PSS_PADDING) != 1) {
+
+#if defined EVP_PKEY_ED25519
+    if (EVP_PKEY_id(key) == EVP_PKEY_ED25519)
+    {
+        if (EVP_DigestSign(ctx, NULL, &siglen, input.base, input.len) != 1) {
             ret = PTLS_ERROR_LIBRARY;
             goto Exit;
         }
-        if (EVP_PKEY_CTX_set_rsa_pss_saltlen(pkey_ctx, -1) != 1) {
-            ret = PTLS_ERROR_LIBRARY;
+
+        if ((ret = ptls_buffer_reserve(outbuf, siglen)) != 0)
             goto Exit;
-        }
-        if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkey_ctx, md) != 1) {
+        
+        if (EVP_DigestSign(ctx, outbuf->base + outbuf->off, &siglen, input.base, input.len) != 1) {
             ret = PTLS_ERROR_LIBRARY;
             goto Exit;
         }
     }
-    if (EVP_DigestSignUpdate(ctx, input.base, input.len) != 1) {
-        ret = PTLS_ERROR_LIBRARY;
-        goto Exit;
+    else 
+#endif
+    {
+        if (EVP_PKEY_id(key) == EVP_PKEY_RSA) {
+            if (EVP_PKEY_CTX_set_rsa_padding(pkey_ctx, RSA_PKCS1_PSS_PADDING) != 1) {
+                ret = PTLS_ERROR_LIBRARY;
+                goto Exit;
+            }
+            if (EVP_PKEY_CTX_set_rsa_pss_saltlen(pkey_ctx, -1) != 1) {
+                ret = PTLS_ERROR_LIBRARY;
+                goto Exit;
+            }
+            if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkey_ctx, md) != 1) {
+                ret = PTLS_ERROR_LIBRARY;
+                goto Exit;
+            }
+        }
+        if (EVP_DigestSignUpdate(ctx, input.base, input.len) != 1) {
+            ret = PTLS_ERROR_LIBRARY;
+            goto Exit;
+        }
+        if (EVP_DigestSignFinal(ctx, NULL, &siglen) != 1) {
+            ret = PTLS_ERROR_LIBRARY;
+            goto Exit;
+        }
+        if ((ret = ptls_buffer_reserve(outbuf, siglen)) != 0)
+            goto Exit;
+        if (EVP_DigestSignFinal(ctx, outbuf->base + outbuf->off, &siglen) != 1) {
+            ret = PTLS_ERROR_LIBRARY;
+            goto Exit;
+        }
     }
-    if (EVP_DigestSignFinal(ctx, NULL, &siglen) != 1) {
-        ret = PTLS_ERROR_LIBRARY;
-        goto Exit;
-    }
-    if ((ret = ptls_buffer_reserve(outbuf, siglen)) != 0)
-        goto Exit;
-    if (EVP_DigestSignFinal(ctx, outbuf->base + outbuf->off, &siglen) != 1) {
-        ret = PTLS_ERROR_LIBRARY;
-        goto Exit;
-    }
+
     outbuf->off += siglen;
 
     ret = 0;
@@ -1054,32 +1085,52 @@
         ret = PTLS_ERROR_NO_MEMORY;
         goto Exit;
     }
-    if (EVP_DigestVerifyInit(ctx, &pkey_ctx, scheme->scheme_md(), NULL, key) != 1) {
-        ret = PTLS_ERROR_LIBRARY;
-        goto Exit;
-    }
-    if (EVP_PKEY_id(key) == EVP_PKEY_RSA) {
-        if (EVP_PKEY_CTX_set_rsa_padding(pkey_ctx, RSA_PKCS1_PSS_PADDING) != 1) {
+
+#if defined EVP_PKEY_ED25519
+    if (EVP_PKEY_id(key) == EVP_PKEY_ED25519)
+    {
+        if (EVP_DigestVerifyInit(ctx, &pkey_ctx, NULL, NULL, key) != 1) {
             ret = PTLS_ERROR_LIBRARY;
             goto Exit;
         }
-        if (EVP_PKEY_CTX_set_rsa_pss_saltlen(pkey_ctx, -1) != 1) {
-            ret = PTLS_ERROR_LIBRARY;
-            goto Exit;
-        }
-        if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkey_ctx, scheme->scheme_md()) != 1) {
+        
+        if (EVP_DigestVerify(ctx, signature.base, signature.len, data.base, data.len) != 1) {
             ret = PTLS_ERROR_LIBRARY;
             goto Exit;
         }
     }
-    if (EVP_DigestVerifyUpdate(ctx, data.base, data.len) != 1) {
-        ret = PTLS_ERROR_LIBRARY;
-        goto Exit;
+    else
+#endif
+    {
+        if (EVP_DigestVerifyInit(ctx, &pkey_ctx, scheme->scheme_md(), NULL, key) != 1) {
+            ret = PTLS_ERROR_LIBRARY;
+            goto Exit;
+        }
+        
+        if (EVP_PKEY_id(key) == EVP_PKEY_RSA) {
+            if (EVP_PKEY_CTX_set_rsa_padding(pkey_ctx, RSA_PKCS1_PSS_PADDING) != 1) {
+                ret = PTLS_ERROR_LIBRARY;
+                goto Exit;
+            }
+            if (EVP_PKEY_CTX_set_rsa_pss_saltlen(pkey_ctx, -1) != 1) {
+                ret = PTLS_ERROR_LIBRARY;
+                goto Exit;
+            }
+            if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkey_ctx, scheme->scheme_md()) != 1) {
+                ret = PTLS_ERROR_LIBRARY;
+                goto Exit;
+            }
+        }
+        if (EVP_DigestVerifyUpdate(ctx, data.base, data.len) != 1) {
+            ret = PTLS_ERROR_LIBRARY;
+            goto Exit;
+        }
+        if (EVP_DigestVerifyFinal(ctx, signature.base, signature.len) != 1) {
+            ret = PTLS_ALERT_DECRYPT_ERROR;
+            goto Exit;
+        }
     }
-    if (EVP_DigestVerifyFinal(ctx, signature.base, signature.len) != 1) {
-        ret = PTLS_ALERT_DECRYPT_ERROR;
-        goto Exit;
-    }
+
     ret = 0;
 
 Exit:
diff --git a/t/openssl.c b/t/openssl.c
index a6f0a06..5ca7bbf 100644
--- a/t/openssl.c
+++ b/t/openssl.c
@@ -138,7 +138,7 @@
         uint8_t sigbuf_small[1024];
 
         ptls_buffer_init(&sigbuf, sigbuf_small, sizeof(sigbuf_small));
-        ok(do_sign(key, &sigbuf, ptls_iovec_init(message, strlen(message)), schemes[i].scheme_md()) == 0);
+        ok(do_sign(key, &sigbuf, ptls_iovec_init(message, strlen(message)), schemes[i].scheme_md != NULL ? schemes[i].scheme_md() : NULL) == 0);
         EVP_PKEY_up_ref(key);
         ok(verify_sign(key, schemes[i].scheme_id, ptls_iovec_init(message, strlen(message)),
                        ptls_iovec_init(sigbuf.base, sigbuf.off)) == 0);
@@ -180,6 +180,23 @@
 #endif
 }
 
+static void test_ed25519_sign(void)
+{
+#if defined EVP_PKEY_ED25519
+    EVP_PKEY *pkey = NULL;
+
+    { /* create pkey */
+        EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_ED25519, NULL);
+        EVP_PKEY_keygen_init(pctx);
+        EVP_PKEY_keygen(pctx, &pkey);
+        EVP_PKEY_CTX_free(pctx);
+    }
+
+    test_sign_verify(pkey, ed25519_signature_schemes);
+    EVP_PKEY_free(pkey);
+#endif
+}
+
 static X509 *x509_from_pem(const char *pem)
 {
     BIO *bio = BIO_new_mem_buf((void *)pem, (int)strlen(pem));
@@ -318,6 +335,7 @@
 
     subtest("rsa-sign", test_rsa_sign);
     subtest("ecdsa-sign", test_ecdsa_sign);
+    subtest("ed25519-sign", test_ed25519_sign);
     subtest("cert-verify", test_cert_verify);
     subtest("picotls", test_picotls);
     test_picotls_esni(esni_private_keys);