diff --git a/res/res_pjsip_diversion.c b/res/res_pjsip_diversion.c
index 08f75e0903..d344214e3b 100644
--- a/res/res_pjsip_diversion.c
+++ b/res/res_pjsip_diversion.c
@@ -120,6 +120,7 @@ static enum AST_REDIRECTING_REASON cause_to_reason(const unsigned long cause) {
 static int add_supported(pjsip_tx_data *tdata)
 {
 	pjsip_supported_hdr *hdr;
+	unsigned int i;
 
 	hdr = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_SUPPORTED, NULL);
 	if (!hdr) {
@@ -132,6 +133,19 @@ static int add_supported(pjsip_tx_data *tdata)
 		pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr *)hdr);
 	}
 
+	/* Asterisk can send multiple "181 Call forwarded" in a single session,
+	 * we might have already modified Supported before
+	 */
+	for (i = 0; i < hdr->count; ++i) {
+		if (pj_stricmp(&hdr->values[i], &HISTINFO_SUPPORTED_NAME) == 0) {
+			return 0;
+		}
+	}
+
+	if (hdr->count >= PJSIP_GENERIC_ARRAY_MAX_COUNT) {
+		return -1;
+	}
+
 	/* add on to the existing Supported header */
 	pj_strassign(&hdr->values[hdr->count++], &HISTINFO_SUPPORTED_NAME);
 
diff --git a/res/res_pjsip_outbound_registration.c b/res/res_pjsip_outbound_registration.c
index 0f590f5364..1b8fbe2d2a 100644
--- a/res/res_pjsip_outbound_registration.c
+++ b/res/res_pjsip_outbound_registration.c
@@ -586,6 +586,7 @@ static int handle_client_registration(void *data)
 
 	if (client_state->support_path) {
 		pjsip_supported_hdr *hdr;
+		int i;
 
 		hdr = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_SUPPORTED, NULL);
 		if (!hdr) {
@@ -599,6 +600,17 @@ static int handle_client_registration(void *data)
 			pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr *)hdr);
 		}
 
+		/* Don't add the value if it's already there */
+		for (i = 0; i < hdr->count; ++i) {
+			if (pj_stricmp(&hdr->values[i], &PATH_NAME) == 0) {
+				return 1;
+			}
+		}
+
+		if (hdr->count >= PJSIP_GENERIC_ARRAY_MAX_COUNT) {
+			return 0;
+		}
+
 		/* add on to the existing Supported header */
 		pj_strassign(&hdr->values[hdr->count++], &PATH_NAME);
 	}
diff --git a/res/res_pjsip_path.c b/res/res_pjsip_path.c
index de231fb2d4..28f2cfd7a2 100644
--- a/res/res_pjsip_path.c
+++ b/res/res_pjsip_path.c
@@ -123,6 +123,7 @@ static int path_get_string(pj_pool_t *pool, struct ast_sip_contact *contact, pj_
 static int add_supported(pjsip_tx_data *tdata)
 {
 	pjsip_supported_hdr *hdr;
+	int i;
 
 	hdr = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_SUPPORTED, NULL);
 	if (!hdr) {
@@ -135,6 +136,17 @@ static int add_supported(pjsip_tx_data *tdata)
 		pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr *)hdr);
 	}
 
+	/* Don't add the value if it's already there */
+	for (i = 0; i < hdr->count; ++i) {
+		if (pj_stricmp(&hdr->values[i], &PATH_SUPPORTED_NAME) == 0) {
+			return 0;
+		}
+	}
+
+	if (hdr->count >= PJSIP_GENERIC_ARRAY_MAX_COUNT) {
+		return -1;
+	}
+
 	/* add on to the existing Supported header */
 	pj_strassign(&hdr->values[hdr->count++], &PATH_SUPPORTED_NAME);