diff -up ./data/reference/extension/curl/55/constants.json.curltls data/reference/extension/curl/55/constants.json
--- ./data/reference/extension/curl/55/constants.json.curltls	2021-02-10 08:41:37.593374602 +0100
+++ ./data/reference/extension/curl/55/constants.json	2021-02-10 08:48:53.129243382 +0100
@@ -1440,26 +1440,31 @@
     },
     {
         "name": "CURL_SSLVERSION_DEFAULT",
+        "optional": true,
         "ext_min": "5.5.0",
         "php_min": "5.5.0"
     },
     {
         "name": "CURL_SSLVERSION_SSLv2",
+        "optional": true,
         "ext_min": "5.5.0",
         "php_min": "5.5.0"
     },
     {
         "name": "CURL_SSLVERSION_SSLv3",
+        "optional": true,
         "ext_min": "5.5.0",
         "php_min": "5.5.0"
     },
     {
         "name": "CURL_SSLVERSION_TLSv1",
+        "optional": true,
         "ext_min": "5.5.0",
         "php_min": "5.5.0"
     },
     {
         "name": "CURL_SSLVERSION_TLSv1_0",
+        "optional": true,
         "ext_min": "5.5.19RC1",
         "php_min": "5.5.19RC1",
         "php_excludes": "5.6.0, 5.6.0RC1, 5.6.0RC2, 5.6.0RC3, 5.6.0RC4, 5.6.1, 5.6.1RC1, 5.6.2",
@@ -1472,6 +1477,7 @@
     },
     {
         "name": "CURL_SSLVERSION_TLSv1_1",
+        "optional": true,
         "ext_min": "5.5.19RC1",
         "php_min": "5.5.19RC1",
         "php_excludes": "5.6.0, 5.6.0RC1, 5.6.0RC2, 5.6.0RC3, 5.6.0RC4, 5.6.1, 5.6.1RC1, 5.6.2",
@@ -1484,6 +1490,7 @@
     },
     {
         "name": "CURL_SSLVERSION_TLSv1_2",
+        "optional": true,
         "ext_min": "5.5.19RC1",
         "php_min": "5.5.19RC1",
         "php_excludes": "5.6.0, 5.6.0RC1, 5.6.0RC2, 5.6.0RC3, 5.6.0RC4, 5.6.1, 5.6.1RC1, 5.6.2",