diff --git a/auth-globalprotect.c b/auth-globalprotect.c
index 5c4dfe73..5b2d3ec1 100644
--- a/auth-globalprotect.c
+++ b/auth-globalprotect.c
@@ -362,11 +362,8 @@ static int gpst_login(struct openconnect_info *vpninfo, int portal, char *pw_or_
 
 		/* submit gateway login (ssl-vpn/login.esp) or portal config (global-protect/getconfig.esp) request */
 		buf_truncate(request_body);
-		buf_append(request_body, "jnlpReady=jnlpReady&ok=Login&direct=yes&clientVer=4100&prot=https:");
-		if (!strcmp(vpninfo->platname, "win"))
-			append_opt(request_body, "clientos", "Windows");
-		else
-			append_opt(request_body, "clientos", vpninfo->platname);
+		buf_append(request_body, "jnlpReady=jnlpReady&ok=Login&direct=yes&clientVer=4100&prot=https:&clientos=Windows");
+		append_opt(request_body, "os-version", vpninfo->platname);
 		append_opt(request_body, "server", vpninfo->hostname);
 		append_opt(request_body, "computer", vpninfo->localname);
 		if (vpninfo->ip_info.addr)
diff --git a/gpst.c b/gpst.c
index 9742fe16..b064a3e5 100644
--- a/gpst.c
+++ b/gpst.c
@@ -590,12 +590,8 @@ static int gpst_get_config(struct openconnect_info *vpninfo)
 	char *xml_buf=NULL;
 
 	/* submit getconfig request */
-	buf_append(request_body, "client-type=1&protocol-version=p1&app-version=3.0.1-10");
+	buf_append(request_body, "client-type=1&protocol-version=p1&app-version=3.0.1-10&clientos=Windows");
 	append_opt(request_body, "os-version", vpninfo->platname);
-	if (!strcmp(vpninfo->platname, "win"))
-		append_opt(request_body, "clientos", "Windows");
-	else
-		append_opt(request_body, "clientos", vpninfo->platname);
 	append_opt(request_body, "hmac-algo", "sha1,md5");
 	append_opt(request_body, "enc-algo", "aes-128-cbc,aes-256-cbc");
 	if (old_addr) {