diff --git a/include/ntapi/nt_port.h b/include/ntapi/nt_port.h
index ff1cdb9..8021768 100644
--- a/include/ntapi/nt_port.h
+++ b/include/ntapi/nt_port.h
@@ -339,6 +339,12 @@ typedef int32_t __stdcall ntapi_tt_port_type_from_guid(
 	__in	const nt_guid *		guid);
 
 
+typedef int32_t __stdcall ntapi_tt_port_prefix_from_type(
+	__out	wchar16_t		(*prefix)[6],
+	__in	nt_port_type		type,
+	__in	nt_port_subtype		subtype);
+
+
 typedef int32_t __stdcall	ntapi_tt_port_generate_keys(
 	__out	nt_port_keys *		keys);
 
diff --git a/include/ntapi/ntapi.h b/include/ntapi/ntapi.h
index 9fcb896..93970e4 100644
--- a/include/ntapi/ntapi.h
+++ b/include/ntapi/ntapi.h
@@ -550,6 +550,7 @@ typedef struct _ntapi_vtbl {
 	/* nt_port.h */
 	ntapi_tt_port_guid_from_type *			tt_port_guid_from_type;
 	ntapi_tt_port_type_from_guid *			tt_port_type_from_guid;
+	ntapi_tt_port_prefix_from_type *		tt_port_prefix_from_type;
 	ntapi_tt_port_generate_keys *			tt_port_generate_keys;
 	ntapi_tt_port_format_keys *			tt_port_format_keys;
 	ntapi_tt_port_name_from_attr *			tt_port_name_from_attr;
diff --git a/src/internal/ntapi.c b/src/internal/ntapi.c
index 51db364..4941400 100644
--- a/src/internal/ntapi.c
+++ b/src/internal/ntapi.c
@@ -386,6 +386,7 @@ static int32_t __fastcall __ntapi_init_once(ntapi_vtbl ** pvtbl)
 	__ntapi->csr_port_handle 				= __ntapi_csr_port_handle;
 	__ntapi->tt_port_guid_from_type				= __ntapi_tt_port_guid_from_type;
 	__ntapi->tt_port_type_from_guid				= __ntapi_tt_port_type_from_guid;
+	__ntapi->tt_port_prefix_from_type			= __ntapi_tt_port_prefix_from_type;
 	__ntapi->tt_port_generate_keys 				= __ntapi_tt_port_generate_keys;
 	__ntapi->tt_port_format_keys 				= __ntapi_tt_port_format_keys;
 	__ntapi->tt_port_name_from_attr 			= __ntapi_tt_port_name_from_attr;
diff --git a/src/internal/ntapi_fnapi.h b/src/internal/ntapi_fnapi.h
index c41dc02..8e900ce 100644
--- a/src/internal/ntapi_fnapi.h
+++ b/src/internal/ntapi_fnapi.h
@@ -202,6 +202,7 @@ NTAPI_UFN(tt_wait_for_dummy_event);
 /* nt_port.h */
 NTAPI_UFN(tt_port_guid_from_type);
 NTAPI_UFN(tt_port_type_from_guid);
+NTAPI_UFN(tt_port_prefix_from_type);
 NTAPI_UFN(tt_port_generate_keys);
 NTAPI_UFN(tt_port_format_keys);
 NTAPI_UFN(tt_port_name_from_attr);
diff --git a/src/port/ntapi_port_name_helper.c b/src/port/ntapi_port_name_helper.c
index e28df8c..fe6a684 100644
--- a/src/port/ntapi_port_name_helper.c
+++ b/src/port/ntapi_port_name_helper.c
@@ -87,6 +87,29 @@ int32_t __stdcall __ntapi_tt_port_type_from_guid(
 }
 
 
+int32_t __stdcall __ntapi_tt_port_prefix_from_type(
+	__out	wchar16_t		(*prefix)[6],
+	__in	nt_port_type		type,
+	__in	nt_port_subtype		subtype)
+{
+	const wchar16_t * svc_prefix;
+
+	if ((type >= NT_PORT_TYPE_CAP) || (subtype >= NT_PORT_SUBTYPE_CAP))
+		return NT_STATUS_INVALID_PARAMETER;
+
+	svc_prefix = __port_service_prefixes[type][subtype];
+
+	prefix[0][0] = svc_prefix[0];
+	prefix[0][1] = svc_prefix[1];
+	prefix[0][2] = svc_prefix[2];
+	prefix[0][3] = svc_prefix[3];
+	prefix[0][4] = svc_prefix[4];
+	prefix[0][5] = svc_prefix[5];
+
+	return NT_STATUS_SUCCESS;
+}
+
+
 int32_t __stdcall __ntapi_tt_port_generate_keys(
 	__out	nt_port_keys *		keys)
 {