diff --git a/plugins/janus_sip.c b/plugins/janus_sip.c
index 0ed13b8c9f..b30b8f7ed3 100644
--- a/plugins/janus_sip.c
+++ b/plugins/janus_sip.c
@@ -120,6 +120,7 @@
 	"outbound_proxy" : "<outbound proxy to use, if any; optional>",
 	"headers" : "<array of key/value objects, to specify custom headers to add to the SIP REGISTER; optional>",
 	"contact_params" : "<array of key/value objects, to specify custom Contact URI params to add to the SIP REGISTER; optional>",
+	"incoming_header_prefixes" : "<array of strings, to specify custom (non-standard) headers to read on incoming SIP events; optional>",
 	"refresh" : <true|false; if true, only uses the SIP REGISTER as an update and not a new registration; optional>",
 	"master_id" : <ID of an already registered account, if this is an helper for multiple calls (more on that later); optional>
 }
@@ -206,6 +207,7 @@
 	"call_id" : "<value of SIP Call-ID header for related call>",
 	"result" : {
 		"event" : "ringing",
+		"headers" : "<object with key/value strings; custom headers extracted from SIP event based on incoming_header_prefix defined in register request; optional>"
 	}
 }
 \endverbatim
@@ -221,7 +223,8 @@
 	"call_id" : "<value of SIP Call-ID header for related call>",
 	"result" : {
 		"event" : "accepted",
-		"username" : "<SIP URI of the callee>"
+		"username" : "<SIP URI of the callee>",
+		"headers" : "<object with key/value strings; custom headers extracted from SIP event based on incoming_header_prefix defined in register request; optional>"
 	}
 }
 \endverbatim
@@ -242,7 +245,8 @@
 	"call_id" : "<value of SIP Call-ID header for related call>",
 	"result" : {
 		"event" : "progress",
-		"username" : "<SIP URI of the callee>"
+		"username" : "<SIP URI of the callee>",
+		"headers" : "<object with key/value strings; custom headers extracted from SIP event based on incoming_header_prefix defined in register request; optional>"
 	}
 }
 \endverbatim
@@ -283,7 +287,8 @@
 		"displayname" : "<display name of the caller, if available; optional>",
 		"referred_by" : "<SIP URI of the transferor, if this is a transfer; optional>",
 		"replaces" : "<call-ID of the call that this is supposed to replace, if this is an attended transfer; optional>",
-		"srtp" : "<whether the caller mandates (sdes_mandatory) or offers (sdes_optional) SRTP support; optional>"
+		"srtp" : "<whether the caller mandates (sdes_mandatory) or offers (sdes_optional) SRTP support; optional>",
+		"headers" : "<object with key/value strings; custom headers extracted from SIP event based on incoming_header_prefix defined in register request; optional>"
 	}
 }
 \endverbatim
@@ -388,7 +393,8 @@
 		"event" : "message",
 		"sender" : "<SIP URI of the message sender>",
 		"displayname" : "<display name of the sender, if available; optional>",
-		"content" : "<content of the message>"
+		"content" : "<content of the message>",
+		"headers" : "<object with key/value strings; custom headers extracted from SIP event based on incoming_header_prefix defined in register request; optional>"
 	}
 }
 \endverbatim
@@ -415,7 +421,8 @@
 		"sender" : "<SIP URI of the message sender>",
 		"displayname" : "<display name of the sender, if available; optional>",
 		"type" : "<content type of the message>",
-		"content" : "<content of the message>"
+		"content" : "<content of the message>",
+		"headers" : "<object with key/value strings; custom headers extracted from SIP event based on incoming_header_prefix defined in register request; optional>"
 	}
 }
 \endverbatim
@@ -445,7 +452,8 @@
 		"notify" : "<name of the event that the user is subscribed to, e.g., 'message-summary'>",
 		"substate" : "<substate of the subscription, e.g., 'active'>",
 		"content-type" : "<content-type of the message>"
-		"content" : "<content of the message>"
+		"content" : "<content of the message>",
+		"headers" : "<object with key/value strings; custom headers extracted from SIP event based on incoming_header_prefix defined in register request; optional>"
 	}
 }
 \endverbatim
@@ -561,7 +569,8 @@
 		"refer_id" : <unique ID, internal to Janus, of this referral>,
 		"refer_to" : "<SIP URI to call>",
 		"referred_by" : "<SIP URI of the transferor; optional>",
-		"replaces" : "<call-ID of the call this transfer is supposed to replace; optional, and only present for attended transfers>"
+		"replaces" : "<call-ID of the call this transfer is supposed to replace; optional, and only present for attended transfers>",
+		"headers" : "<object with key/value strings; custom headers extracted from SIP event based on incoming_header_prefix defined in register request; optional>"
 	}
 }
 \endverbatim
@@ -697,7 +706,8 @@ static struct janus_json_parameter register_parameters[] = {
 	{"headers", JSON_OBJECT, 0},
 	{"contact_params", JSON_OBJECT, 0},
 	{"master_id", JANUS_JSON_INTEGER, 0},
-	{"refresh", JANUS_JSON_BOOL, 0}
+	{"refresh", JANUS_JSON_BOOL, 0},
+	{"incoming_header_prefixes", JSON_ARRAY, 0}
 };
 static struct janus_json_parameter subscribe_parameters[] = {
 	{"to", JSON_STRING, 0},
@@ -963,6 +973,7 @@ typedef struct janus_sip_session {
 	janus_refcount ref;
 	janus_mutex mutex;
 	char *hangup_reason_header;
+	GList *incoming_header_prefixes;
 } janus_sip_session;
 static GHashTable *sessions;
 static GHashTable *identities;
@@ -1072,6 +1083,10 @@ static void janus_sip_session_free(const janus_refcount *session_ref) {
 		g_free(session->hangup_reason_header);
 		session->hangup_reason_header = NULL;
 	}
+	if(session->incoming_header_prefixes) {
+		g_list_free_full(session->incoming_header_prefixes, g_free);
+		session->incoming_header_prefixes = NULL;
+	}
 	janus_sip_srtp_cleanup(session);
 	g_free(session);
 }
@@ -1385,6 +1400,29 @@ static void janus_sip_remove_quotes(char *str) {
 	}
 }
 
+static json_t *janus_sip_get_incoming_headers(const sip_t *sip, const janus_sip_session *session) {
+	json_t *headers = json_object();
+	if(!sip)
+		return headers;
+	sip_unknown_t *unknown_header = sip->sip_unknown;
+	while(unknown_header != NULL) {
+		GList *temp = session->incoming_header_prefixes;
+		while(temp != NULL) {
+			char *header_prefix = (char *) temp->data;
+			if(header_prefix != NULL && unknown_header->un_name != NULL) {
+				if(strncasecmp(unknown_header->un_name, header_prefix, strlen(header_prefix)) == 0) {
+					const char *header_name = g_strdup(unknown_header->un_name);
+					json_object_set(headers, header_name, json_string(unknown_header->un_value));
+					break;
+				}
+			}
+			temp = temp->next;
+		}
+		unknown_header = unknown_header->un_next;
+	}
+	return headers;
+}
+
 /* Error codes */
 #define JANUS_SIP_ERROR_UNKNOWN_ERROR		499
 #define JANUS_SIP_ERROR_NO_MESSAGE			440
@@ -2706,6 +2744,19 @@ static void *janus_sip_handler(void *data) {
 				g_hash_table_insert(masters, GUINT_TO_POINTER(session->master_id), session);
 				janus_mutex_unlock(&sessions_mutex);
 			}
+
+			json_t *header_prefixes_json = json_object_get(root, "incoming_header_prefixes");
+			if(header_prefixes_json) {
+				size_t index = 0;
+				json_t *value = NULL;
+
+				json_array_foreach(header_prefixes_json, index, value) {
+					const char *header_prefix = json_string_value(value);
+					if(header_prefix)
+						session->incoming_header_prefixes = g_list_append(session->incoming_header_prefixes, g_strdup(header_prefix));
+				}
+			}
+
 			/* If this is a refresh, get rid of the old values */
 			if(refresh) {
 				/* Cleanup old values */
@@ -4465,6 +4516,10 @@ void janus_sip_sofia_callback(nua_event_t event, int status, char const *phrase,
 			if(sip->sip_from && sip->sip_from->a_display) {
 				json_object_set_new(calling, "displayname", json_string(sip->sip_from->a_display));
 			}
+			if(session->incoming_header_prefixes) {
+				json_t *headers = janus_sip_get_incoming_headers(sip, session);
+				json_object_set_new(calling, "headers", headers);
+			}
 			char *referred_by = NULL;
 			if(sip->sip_referred_by && sip->sip_referred_by->b_url) {
 				char *rby_text = url_as_string(session->stack->s_home, sip->sip_referred_by->b_url);
@@ -4583,6 +4638,10 @@ void janus_sip_sofia_callback(nua_event_t event, int status, char const *phrase,
 				json_object_set_new(result, "replaces", json_string(replaces));
 				g_free(replaces);
 			}
+			if(session->incoming_header_prefixes) {
+				json_t *headers = janus_sip_get_incoming_headers(sip, session);
+				json_object_set_new(result, "headers", headers);
+			}
 			su_free(session->stack->s_home, refer_to);
 			if(custom_headers != NULL)
 				su_free(session->stack->s_home, custom_headers);
@@ -4615,6 +4674,10 @@ void janus_sip_sofia_callback(nua_event_t event, int status, char const *phrase,
 			}
 			json_object_set_new(result, "type", json_string(type));
 			json_object_set_new(result, "content", json_string(payload));
+			if(session->incoming_header_prefixes) {
+				json_t *headers = janus_sip_get_incoming_headers(sip, session);
+				json_object_set_new(result, "headers", headers);
+			}
 			json_object_set_new(info, "result", result);
 			int ret = gateway->push_event(session->handle, &janus_sip_plugin, session->transaction, info, NULL);
 			JANUS_LOG(LOG_VERB, "  >> Pushing event to peer: %d (%s)\n", ret, janus_get_api_error(ret));
@@ -4645,6 +4708,10 @@ void janus_sip_sofia_callback(nua_event_t event, int status, char const *phrase,
 				json_object_set_new(result, "displayname", json_string(sip->sip_from->a_display));
 			}
 			json_object_set_new(result, "content", json_string(payload));
+			if(session->incoming_header_prefixes) {
+				json_t *headers = janus_sip_get_incoming_headers(sip, session);
+				json_object_set_new(result, "headers", headers);
+			}
 			json_object_set_new(message, "result", result);
 			int ret = gateway->push_event(session->handle, &janus_sip_plugin, session->transaction, message, NULL);
 			JANUS_LOG(LOG_VERB, "  >> Pushing event to peer: %d (%s)\n", ret, janus_get_api_error(ret));
@@ -4681,6 +4748,10 @@ void janus_sip_sofia_callback(nua_event_t event, int status, char const *phrase,
 			if(sip->sip_content_type != NULL)
 				json_object_set_new(result, "content-type", json_string(sip->sip_content_type->c_type));
 			json_object_set_new(result, "content", json_string(sip->sip_payload->pl_data));
+			if(session->incoming_header_prefixes) {
+				json_t *headers = janus_sip_get_incoming_headers(sip, session);
+				json_object_set_new(result, "headers", headers);
+			}
 			json_object_set_new(notify, "result", result);
 			int ret = gateway->push_event(session->handle, &janus_sip_plugin, session->transaction, notify, NULL);
 			JANUS_LOG(LOG_VERB, "  >> Pushing event to peer: %d (%s)\n", ret, janus_get_api_error(ret));
@@ -4768,6 +4839,10 @@ void janus_sip_sofia_callback(nua_event_t event, int status, char const *phrase,
 					json_object_set_new(ringing, "sip", json_string("event"));
 					json_t *result = json_object();
 					json_object_set_new(result, "event", json_string("ringing"));
+					if(session->incoming_header_prefixes) {
+						json_t *headers = janus_sip_get_incoming_headers(sip, session);
+						json_object_set_new(result, "headers", headers);
+					}
 					json_object_set_new(ringing, "result", result);
 					json_object_set_new(ringing, "call_id", json_string(session->callid));
 					int ret = gateway->push_event(session->handle, &janus_sip_plugin, session->transaction, ringing, NULL);
@@ -4975,6 +5050,10 @@ void janus_sip_sofia_callback(nua_event_t event, int status, char const *phrase,
 			json_object_set_new(calling, "username", json_string(session->callee));
 			if(is_focus)
 				json_object_set_new(calling, "isfocus", json_true());
+			if(session->incoming_header_prefixes) {
+				json_t *headers = janus_sip_get_incoming_headers(sip, session);
+				json_object_set_new(calling, "headers", headers);
+			}
 			json_object_set_new(call, "result", calling);
 			json_object_set_new(call, "call_id", json_string(session->callid));
 			int ret = gateway->push_event(session->handle, &janus_sip_plugin, session->transaction, call, jsep);
@@ -5137,6 +5216,10 @@ void janus_sip_sofia_callback(nua_event_t event, int status, char const *phrase,
 				json_object_set_new(result, "event", json_string("registration_failed"));
 				json_object_set_new(result, "code", json_integer(status));
 				json_object_set_new(result, "reason", json_string(phrase ? phrase : ""));
+				if(session->incoming_header_prefixes) {
+					json_t *headers = janus_sip_get_incoming_headers(sip, session);
+					json_object_set_new(result, "headers", headers);
+				}
 				json_object_set_new(event, "result", result);
 				int ret = gateway->push_event(session->handle, &janus_sip_plugin, session->transaction, event, NULL);
 				JANUS_LOG(LOG_VERB, "  >> Pushing event to peer: %d (%s)\n", ret, janus_get_api_error(ret));
@@ -5161,6 +5244,10 @@ void janus_sip_sofia_callback(nua_event_t event, int status, char const *phrase,
 				json_t *result = json_object();
 				json_object_set_new(result, "event", json_string("subscribe_succeeded"));
 				json_object_set_new(result, "code", json_integer(status));
+				if(session->incoming_header_prefixes) {
+					json_t *headers = janus_sip_get_incoming_headers(sip, session);
+					json_object_set_new(result, "headers", headers);
+				}
 				json_object_set_new(result, "reason", json_string(phrase ? phrase : ""));
 				json_object_set_new(event, "result", result);
 				int ret = gateway->push_event(session->handle, &janus_sip_plugin, session->transaction, event, NULL);
@@ -5227,6 +5314,10 @@ void janus_sip_sofia_callback(nua_event_t event, int status, char const *phrase,
 				json_object_set_new(result, "event", json_string("subscribe_failed"));
 				json_object_set_new(result, "code", json_integer(status));
 				json_object_set_new(result, "reason", json_string(phrase ? phrase : ""));
+				if(session->incoming_header_prefixes) {
+					json_t *headers = janus_sip_get_incoming_headers(sip, session);
+					json_object_set_new(result, "headers", headers);
+				}
 				json_object_set_new(event, "result", result);
 				int ret = gateway->push_event(session->handle, &janus_sip_plugin, session->transaction, event, NULL);
 				JANUS_LOG(LOG_VERB, "  >> Pushing event to peer: %d (%s)\n", ret, janus_get_api_error(ret));