diff --git a/lib/include/chiaki/session.h b/lib/include/chiaki/session.h
index d090529..54dfad4 100644
--- a/lib/include/chiaki/session.h
+++ b/lib/include/chiaki/session.h
@@ -38,10 +38,14 @@
 extern "C" {
 #endif
 
-#define CHIAKI_RP_APPLICATION_REASON_REGIST_FAILED	0x80108b09
-#define CHIAKI_RP_APPLICATION_REASON_INVALID_PSN_ID	0x80108b02
-#define CHIAKI_RP_APPLICATION_REASON_IN_USE			0x80108b10
-#define CHIAKI_RP_APPLICATION_REASON_CRASH			0x80108b15
+#define CHIAKI_RP_APPLICATION_REASON_REGIST_FAILED		0x80108b09
+#define CHIAKI_RP_APPLICATION_REASON_INVALID_PSN_ID		0x80108b02
+#define CHIAKI_RP_APPLICATION_REASON_IN_USE				0x80108b10
+#define CHIAKI_RP_APPLICATION_REASON_CRASH				0x80108b15
+#define CHIAKI_RP_APPLICATION_REASON_CLIENT_OUTDATED	0x80108b11
+// unknown: 0x80108bff
+
+#define CHIAKI_RP_CLIENT_VERSION						"9.0"
 
 const char *chiaki_rp_application_reason_string(uint32_t reason);
 
diff --git a/lib/src/ctrl.c b/lib/src/ctrl.c
index 39024ce..3d7c2e2 100644
--- a/lib/src/ctrl.c
+++ b/lib/src/ctrl.c
@@ -570,7 +570,7 @@ static ChiakiErrorCode ctrl_connect(ChiakiCtrl *ctrl)
 			"Connection: keep-alive\r\n"
 			"Content-Length: 0\r\n"
 			"RP-Auth: %s\r\n"
-			"RP-Version: 8.0\r\n"
+			"RP-Version: " CHIAKI_RP_CLIENT_VERSION "\r\n"
 			"RP-Did: %s\r\n"
 			"RP-ControllerType: 3\r\n"
 			"RP-ClientType: 11\r\n"
diff --git a/lib/src/session.c b/lib/src/session.c
index a061ad6..9ea2e21 100644
--- a/lib/src/session.c
+++ b/lib/src/session.c
@@ -57,6 +57,8 @@ const char *chiaki_rp_application_reason_string(uint32_t reason)
 			return "Remote is already in use";
 		case CHIAKI_RP_APPLICATION_REASON_CRASH:
 			return "Remote Play on Console crashed";
+		case CHIAKI_RP_APPLICATION_REASON_CLIENT_OUTDATED:
+			return "Client outdated";
 		default:
 			return "unknown";
 	}
@@ -648,7 +650,7 @@ static bool session_thread_request_session(ChiakiSession *session)
 			"Connection: close\r\n"
 			"Content-Length: 0\r\n"
 			"RP-Registkey: %s\r\n"
-			"Rp-Version: 8.0\r\n"
+			"Rp-Version: " CHIAKI_RP_CLIENT_VERSION "\r\n"
 			"\r\n";
 
 	size_t regist_key_len = sizeof(session->connect_info.regist_key);