diff --git a/CHANGES.txt b/CHANGES.txt
index fdf287b..7437c63 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,8 @@
+## unreleased
+
+* Add support for proxy types CURLPROXY_HTTPS and CURLPROXY_HTTPS2.
+  (Volker Diels-Grabsch)
+
 ## 0.10.0 - 14 May 2025
 
 * Transition from the ocurl package name to curl.
diff --git a/config/discover.ml b/config/discover.ml
index 00f46be..f7a9fc6 100644
--- a/config/discover.ml
+++ b/config/discover.ml
@@ -303,6 +303,9 @@ let curl_h_declarations = [
   "CURLOPT_WRITEINFO";
   "CURLOPT_XFERINFOFUNCTION";
 
+  "CURLPROXY_HTTPS";
+  "CURLPROXY_HTTPS2";
+
   "CURLSSLBACKEND_BEARSSL";
   "CURLSSLBACKEND_GNUTLS";
   "CURLSSLBACKEND_GSKIT";
diff --git a/curl-helper.c b/curl-helper.c
index b7038ca..ea51f8c 100644
--- a/curl-helper.c
+++ b/curl-helper.c
@@ -3243,8 +3243,14 @@ static void handle_PROXYTYPE(Connection *conn, value option)
       case 3: proxy_type = CURLPROXY_SOCKS5; break;
       case 4: proxy_type = CURLPROXY_SOCKS4A; break;
       case 5: proxy_type = CURLPROXY_SOCKS5_HOSTNAME; break;
+#if HAVE_DECL_CURLPROXY_HTTPS
+      case 6: proxy_type = CURLPROXY_HTTPS; break;
+#endif
+#if HAVE_DECL_CURLPROXY_HTTPS2
+      case 7: proxy_type = CURLPROXY_HTTPS2; break;
+#endif
       default:
-        caml_failwith("Invalid curl proxy type");
+        caml_failwith("Unsupported curl proxy type");
     }
 
     result = curl_easy_setopt(conn->handle,
diff --git a/curl.ml b/curl.ml
index cefa4d4..65c3218 100644
--- a/curl.ml
+++ b/curl.ml
@@ -244,12 +244,14 @@ type curlSeek =
   | SEEK_END
 
 type curlProxyType =
-  | CURLPROXY_HTTP
-  | CURLPROXY_HTTP_1_0 (** added in 7.19.4 *)
-  | CURLPROXY_SOCKS4 (** added in 7.15.2 *)
-  | CURLPROXY_SOCKS5
-  | CURLPROXY_SOCKS4A (** added in 7.18.0 *)
-  | CURLPROXY_SOCKS5_HOSTNAME (** added in 7.18.0 *)
+  | CURLPROXY_HTTP (** since libcurl 7.10 *)
+  | CURLPROXY_HTTP_1_0 (** since libcurl 7.19.4 *)
+  | CURLPROXY_SOCKS4 (** since libcurl 7.15.2 *)
+  | CURLPROXY_SOCKS5 (** since libcurl 7.10 *)
+  | CURLPROXY_SOCKS4A (** since libcurl 7.18.0 *)
+  | CURLPROXY_SOCKS5_HOSTNAME (** since libcurl 7.18.0 *)
+  | CURLPROXY_HTTPS (** since libcurl 7.52.0 *)
+  | CURLPROXY_HTTPS2 (** since libcurl 8.1.0 *)
 
 type curlSockType =
   | CURLSOCKTYPE_IPCXN
diff --git a/curl.mli b/curl.mli
index 8efd532..69e21dc 100644
--- a/curl.mli
+++ b/curl.mli
@@ -252,12 +252,14 @@ type curlSeek =
   | SEEK_END
 
 type curlProxyType =
-  | CURLPROXY_HTTP
+  | CURLPROXY_HTTP (** since libcurl 7.10 *)
   | CURLPROXY_HTTP_1_0 (** since libcurl 7.19.4 *)
   | CURLPROXY_SOCKS4 (** since libcurl 7.15.2 *)
-  | CURLPROXY_SOCKS5
+  | CURLPROXY_SOCKS5 (** since libcurl 7.10 *)
   | CURLPROXY_SOCKS4A (** since libcurl 7.18.0 *)
   | CURLPROXY_SOCKS5_HOSTNAME (** since libcurl 7.18.0 *)
+  | CURLPROXY_HTTPS (** since libcurl 7.52.0 *)
+  | CURLPROXY_HTTPS2 (** since libcurl 8.1.0 *)
 
 type curlSockType =
   | CURLSOCKTYPE_IPCXN