diff --git a/dlls/crypt32/msg.c b/dlls/crypt32/msg.c
index 8a1fea0e241..ba75cb60a24 100644
--- a/dlls/crypt32/msg.c
+++ b/dlls/crypt32/msg.c
@@ -865,12 +865,19 @@ static BOOL CSignedEncodeMsg_GetParam(HCRYPTMSG hCryptMsg, DWORD dwParamType,
             ret = CryptGetHashParam(msg->signerHandles[dwIndex].hash,
              HP_HASHVAL, pvData, pcbData, 0);
         break;
+    case CMSG_ENCODED_SIGNER:
+        if (dwIndex >= msg->info.cSignerInfo)
+            SetLastError(CRYPT_E_INVALID_INDEX);
+        else
+            ret = CryptEncodeObjectEx(X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,
+             PKCS7_SIGNER_INFO, &msg->info.rgSignerInfo[dwIndex], 0, NULL,
+             pvData, pcbData);
+        break;
     case CMSG_VERSION_PARAM:
         ret = CRYPT_CopyParam(pvData, pcbData, (const BYTE *)&msg->info.version,
          sizeof(msg->info.version));
         break;
     default:
-        FIXME("unimplemented for %d\n", dwParamType);
         SetLastError(CRYPT_E_INVALID_MSG_TYPE);
     }
     return ret;
diff --git a/dlls/crypt32/tests/msg.c b/dlls/crypt32/tests/msg.c
index 8665594a0d5..3bd0882102b 100644
--- a/dlls/crypt32/tests/msg.c
+++ b/dlls/crypt32/tests/msg.c
@@ -1256,6 +1256,15 @@ static const BYTE signedContent[] = {
 static const BYTE signedHash[] = {
 0x08,0xd6,0xc0,0x5a,0x21,0x51,0x2a,0x79,0xa1,0xdf,0xeb,0x9d,0x2a,0x8f,0x26,
 0x2f };
+static const BYTE signedEncodedSigner[] = {
+0x30,0x75,0x02,0x01,0x01,0x30,0x1a,0x30,0x15,0x31,0x13,0x30,0x11,0x06,0x03,
+0x55,0x04,0x03,0x13,0x0a,0x4a,0x75,0x61,0x6e,0x20,0x4c,0x61,0x6e,0x67,0x00,
+0x02,0x01,0x01,0x30,0x0c,0x06,0x08,0x2a,0x86,0x48,0x86,0xf7,0x0d,0x02,0x05,
+0x05,0x00,0x30,0x04,0x06,0x00,0x05,0x00,0x04,0x40,0x81,0xa6,0x70,0xb3,0xef,
+0x59,0xd1,0x66,0xd1,0x9b,0xc0,0x9a,0xb6,0x9a,0x5e,0x6d,0x6f,0x6d,0x0d,0x59,
+0xa9,0xaa,0x6e,0xe9,0x2c,0xa0,0x1e,0xee,0xc2,0x60,0xbc,0x59,0xbe,0x3f,0x63,
+0x06,0x8d,0xc9,0x11,0x1d,0x23,0x64,0x92,0xef,0x2e,0xfc,0x57,0x29,0xa4,0xaf,
+0xe0,0xee,0x93,0x19,0x39,0x51,0xe4,0x44,0xb8,0x0b,0x28,0xf4,0xa8,0x0d };
 static BYTE cert[] = {
 0x30,0x7a,0x02,0x01,0x01,0x30,0x02,0x06,0x00,0x30,0x15,0x31,0x13,0x30,0x11,
 0x06,0x03,0x55,0x04,0x03,0x13,0x0a,0x4a,0x75,0x61,0x6e,0x20,0x4c,0x61,0x6e,
@@ -1427,6 +1436,8 @@ static void test_signed_msg_encoding(void)
     ret = CryptMsgGetParam(msg, CMSG_COMPUTED_HASH_PARAM, 1, NULL, &size);
     ok(!ret && GetLastError() == CRYPT_E_INVALID_INDEX,
      "Expected CRYPT_E_INVALID_INDEX, got %x\n", GetLastError());
+    check_param("detached signed encoded signer", msg, CMSG_ENCODED_SIGNER,
+     signedEncodedSigner, sizeof(signedEncodedSigner));
 
     CryptMsgClose(msg);
 
@@ -1536,7 +1547,6 @@ static void test_signed_msg_get_param(void)
     size = 0;
     SetLastError(0xdeadbeef);
     ret = CryptMsgGetParam(msg, CMSG_ENCODED_SIGNER, 0, NULL, &size);
-    todo_wine
     ok(!ret && GetLastError() == CRYPT_E_INVALID_INDEX,
      "Expected CRYPT_E_INVALID_INDEX, got %x\n", GetLastError());
     SetLastError(0xdeadbeef);
@@ -1573,14 +1583,12 @@ static void test_signed_msg_get_param(void)
      */
     size = 0;
     ret = CryptMsgGetParam(msg, CMSG_ENCODED_SIGNER, 0, NULL, &size);
-    todo_wine
     ok(ret, "CryptMsgGetParam failed: %x\n", GetLastError());
     ret = CryptMsgGetParam(msg, CMSG_COMPUTED_HASH_PARAM, 0, NULL, &size);
     ok(ret, "CryptMsgGetParam failed: %x\n", GetLastError());
     size = 0;
     SetLastError(0xdeadbeef);
     ret = CryptMsgGetParam(msg, CMSG_ENCODED_SIGNER, 1, NULL, &size);
-    todo_wine
     ok(!ret && GetLastError() == CRYPT_E_INVALID_INDEX,
      "Expected CRYPT_E_INVALID_INDEX, got %x\n", GetLastError());
     SetLastError(0xdeadbeef);