diff --git a/src/core/ktcpsocket.h b/src/core/ktcpsocket.h
--- a/src/core/ktcpsocket.h
+++ b/src/core/ktcpsocket.h
@@ -163,6 +163,7 @@
         TlsV1_0 = TlsV1,
         TlsV1_1 = 0x40,
         TlsV1_2 = 0x80,
+        TlsV1_3 = 0x100,
         AnySslVersion = SslV2 | SslV3 | TlsV1
     };
     Q_DECLARE_FLAGS(SslVersions, SslVersion)
diff --git a/src/core/ktcpsocket.cpp b/src/core/ktcpsocket.cpp
--- a/src/core/ktcpsocket.cpp
+++ b/src/core/ktcpsocket.cpp
@@ -46,6 +46,10 @@
         return KTcpSocket::TlsV1_1;
     case QSsl::TlsV1_2:
         return KTcpSocket::TlsV1_2;
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 12, 0))
+    case QSsl::TlsV1_3:
+        return KTcpSocket::TlsV1_3;
+#endif
     case QSsl::AnyProtocol:
         return KTcpSocket::AnySslVersion;
     case QSsl::TlsV1SslV3:
@@ -67,6 +71,9 @@
     KTcpSocket::SslVersions validVersions(KTcpSocket::SslV2 | KTcpSocket::SslV3 | KTcpSocket::TlsV1);
     validVersions |= KTcpSocket::TlsV1_1;
     validVersions |= KTcpSocket::TlsV1_2;
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 12, 0))
+    validVersions |= KTcpSocket::TlsV1_3;
+#endif
     validVersions |= KTcpSocket::TlsV1SslV3;
     validVersions |= KTcpSocket::SecureProtocols;
 
@@ -85,6 +92,10 @@
         return QSsl::TlsV1_1;
     case KTcpSocket::TlsV1_2:
         return QSsl::TlsV1_2;
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 12, 0))
+    case KTcpSocket::TlsV1_3:
+        return QSsl::TlsV1_3;
+#endif
     case KTcpSocket::TlsV1SslV3:
         return QSsl::TlsV1SslV3;
     case KTcpSocket::SecureProtocols:
@@ -109,6 +120,10 @@
         return QStringLiteral("TLSv1.1");
     case QSsl::TlsV1_2:
         return QStringLiteral("TLSv1.2");
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 12, 0))
+    case QSsl::TlsV1_3:
+        return QStringLiteral("TLSv1.3");
+#endif
     default:
         return QStringLiteral("Unknown");;
     }