diff --git a/include/osmocom/core/gsmtap.h b/include/osmocom/core/gsmtap.h
index 0b647b2..c1c53d0 100644
--- a/include/osmocom/core/gsmtap.h
+++ b/include/osmocom/core/gsmtap.h
@@ -143,6 +143,74 @@
 /* IANA-assigned well-known UDP port for GSMTAP messages */
 #define GSMTAP_UDP_PORT			4729
 
+/* UMTS RRC message types */
+enum {
+	GSMTAP_RRC_SUB_DL_DCCH_Message = 0,
+	GSMTAP_RRC_SUB_UL_DCCH_Message,
+	GSMTAP_RRC_SUB_DL_CCCH_Message,
+	GSMTAP_RRC_SUB_UL_CCCH_Message,
+	GSMTAP_RRC_SUB_PCCH_Message,
+	GSMTAP_RRC_SUB_DL_SHCCH_Message,
+	GSMTAP_RRC_SUB_UL_SHCCH_Message,
+	GSMTAP_RRC_SUB_BCCH_FACH_Message,
+	GSMTAP_RRC_SUB_BCCH_BCH_Message,
+	GSMTAP_RRC_SUB_MCCH_Message,
+	GSMTAP_RRC_SUB_MSCH_Message,
+	GSMTAP_RRC_SUB_HandoverToUTRANCommand,
+	GSMTAP_RRC_SUB_InterRATHandoverInfo,
+	GSMTAP_RRC_SUB_SystemInformation_BCH,
+	GSMTAP_RRC_SUB_System_Information_Container,
+	GSMTAP_RRC_SUB_UE_RadioAccessCapabilityInfo,
+	GSMTAP_RRC_SUB_MasterInformationBlock,
+	GSMTAP_RRC_SUB_SysInfoType1,
+	GSMTAP_RRC_SUB_SysInfoType2,
+	GSMTAP_RRC_SUB_SysInfoType3,
+	GSMTAP_RRC_SUB_SysInfoType4,
+	GSMTAP_RRC_SUB_SysInfoType5,
+	GSMTAP_RRC_SUB_SysInfoType5bis,
+	GSMTAP_RRC_SUB_SysInfoType6,
+	GSMTAP_RRC_SUB_SysInfoType7,
+	GSMTAP_RRC_SUB_SysInfoType8,
+	GSMTAP_RRC_SUB_SysInfoType9,
+	GSMTAP_RRC_SUB_SysInfoType10,
+	GSMTAP_RRC_SUB_SysInfoType11,
+	GSMTAP_RRC_SUB_SysInfoType11bis,
+	GSMTAP_RRC_SUB_SysInfoType12,
+	GSMTAP_RRC_SUB_SysInfoType13,
+	GSMTAP_RRC_SUB_SysInfoType13_1,
+	GSMTAP_RRC_SUB_SysInfoType13_2,
+	GSMTAP_RRC_SUB_SysInfoType13_3,
+	GSMTAP_RRC_SUB_SysInfoType13_4,
+	GSMTAP_RRC_SUB_SysInfoType14,
+	GSMTAP_RRC_SUB_SysInfoType15,
+	GSMTAP_RRC_SUB_SysInfoType15bis,
+	GSMTAP_RRC_SUB_SysInfoType15_1,
+	GSMTAP_RRC_SUB_SysInfoType15_1bis,
+	GSMTAP_RRC_SUB_SysInfoType15_2,
+	GSMTAP_RRC_SUB_SysInfoType15_2bis,
+	GSMTAP_RRC_SUB_SysInfoType15_2ter,
+	GSMTAP_RRC_SUB_SysInfoType15_3,
+	GSMTAP_RRC_SUB_SysInfoType15_3bis,
+	GSMTAP_RRC_SUB_SysInfoType15_4,
+	GSMTAP_RRC_SUB_SysInfoType15_5,
+	GSMTAP_RRC_SUB_SysInfoType15_6,
+	GSMTAP_RRC_SUB_SysInfoType15_7,
+	GSMTAP_RRC_SUB_SysInfoType15_8,
+	GSMTAP_RRC_SUB_SysInfoType16,
+	GSMTAP_RRC_SUB_SysInfoType17,
+	GSMTAP_RRC_SUB_SysInfoType18,
+	GSMTAP_RRC_SUB_SysInfoType19,
+	GSMTAP_RRC_SUB_SysInfoType20,
+	GSMTAP_RRC_SUB_SysInfoType21,
+	GSMTAP_RRC_SUB_SysInfoType22,
+	GSMTAP_RRC_SUB_SysInfoTypeSB1,
+	GSMTAP_RRC_SUB_SysInfoTypeSB2,
+	GSMTAP_RRC_SUB_ToTargetRNC_Container,
+	GSMTAP_RRC_SUB_TargetRNC_ToSourceRNC_Container,
+
+	GSMTAP_RRC_SUB_MAX
+};
+
 /* ====== DO NOT MAKE UNAPPROVED MODIFICATIONS HERE ===== */
 struct gsmtap_hdr {
 	uint8_t version;	/* version, set to 0x01 currently */