diff --git a/lib/reg/pn.c b/lib/reg/pn.c
index 63cb0d88a56..da3ce06f430 100644
--- a/lib/reg/pn.c
+++ b/lib/reg/pn.c
@@ -278,7 +278,7 @@ enum pn_action pn_inspect_ct_params(struct sip_msg *req, const str *ct_uri)
 	int i, is_cap_query = 1, is_handled_upstream = 0;
 
 	if (parse_uri(ct_uri->s, ct_uri->len, &puri) != 0) {
-		LM_ERR("failed to parse URI: '%.*s'\n", ct_uri->len, ct_uri->s);
+		LM_ERR("failed to parse Contact URI '%.*s'\n", ct_uri->len, ct_uri->s);
 		return -1;
 	}
 
@@ -357,12 +357,21 @@ next_param:;
 int pn_inspect_request(struct sip_msg *req, const str *ct_uri,
                        struct save_ctx *sctx)
 {
+	int rc;
+
 	if (sctx->cmatch.mode != CT_MATCH_NONE) {
 		LM_DBG("skip PN processing, matching mode already enforced\n");
 		return 0;
 	}
 
-	switch (pn_inspect_ct_params(req, ct_uri)) {
+	rc = pn_inspect_ct_params(req, ct_uri);
+	if (rc < 0) {
+		rerrno = R_PARSE_CONT;
+		LM_DBG("failed to parse Contact URI\n");
+		return -1;
+	}
+
+	switch (rc) {
 	case PN_NONE:
 		LM_DBG("Contact URI has no PN params\n");
 		break;
diff --git a/modules/mid_registrar/save.c b/modules/mid_registrar/save.c
index 837974bbe5b..1a6d5ded779 100644
--- a/modules/mid_registrar/save.c
+++ b/modules/mid_registrar/save.c
@@ -2517,8 +2517,8 @@ int mid_reg_save(struct sip_msg *msg, udomain_t *d, str *flags_str,
 	}
 
 	if (pn_enable && pn_inspect_request(msg, &c->uri, &sctx) != 0) {
-		LM_DBG("SIP PN processing failed\n");
-		goto quick_reply;
+		LM_DBG("SIP PN processing failed (%d)\n", rerrno);
+		goto out_error;
 	}
 
 	/* mid-registrar always rewrites the Contact, so any Path hf must go! */
diff --git a/modules/registrar/save.c b/modules/registrar/save.c
index 720f1855347..a50dde51e0d 100644
--- a/modules/registrar/save.c
+++ b/modules/registrar/save.c
@@ -671,7 +671,7 @@ int save_aux(struct sip_msg* _m, str* forced_binding, void* _d, str* flags_s,
 		}
 	} else {
 		if (pn_enable && pn_inspect_request(_m, &c->uri, &sctx) != 0) {
-			LM_DBG("SIP PN processing failed\n");
+			LM_DBG("SIP PN processing failed (%d)\n", rerrno);
 			goto error;
 		}
 
diff --git a/parser/parse_uri.c b/parser/parse_uri.c
index 8a49154d4c7..364d91c1f27 100644
--- a/parser/parse_uri.c
+++ b/parser/parse_uri.c
@@ -543,6 +543,16 @@ int parse_uri(char* buf, int len, struct sip_uri* uri)
 						state=URI_PARAM_P; \
 				} \
 				break
+#define param_xswitch1(old_state, c1, new_state) \
+			case old_state: \
+				switch(*p){ \
+					case c1: \
+						state=(new_state); \
+						break; \
+					default: \
+						goto error_bad_char; \
+				} \
+				break
 #define param_switch_big(old_state, c1, c2, d1, d2, new_state_c, new_state_d) \
 			case old_state : \
 				switch(*p){ \
@@ -1239,7 +1249,7 @@ int parse_uri(char* buf, int len, struct sip_uri* uri)
 
 			/* pn-prid */
 			param_switch(PN2_I, 'd', 'D', PN2_D);
-			param_switch1(PN2_D, '=', PN2_eq);
+			param_xswitch1(PN2_D, '=', PN2_eq);
 			case PN2_eq:
 				param=&uri->pn_prid;
 				param_val=&uri->pn_prid_val;
@@ -1255,7 +1265,7 @@ int parse_uri(char* buf, int len, struct sip_uri* uri)
 			param_switch(PN3_A, 'r', 'R', PN3_R);
 			param_switch(PN3_R, 'a', 'A', PN3_A2);
 			param_switch(PN3_A2, 'm', 'M', PN3_M);
-			param_switch1(PN3_M, '=', PN3_eq);
+			param_xswitch1(PN3_M, '=', PN3_eq);
 			case PN3_eq:
 				param=&uri->pn_param;
 				param_val=&uri->pn_param_val;
@@ -1270,7 +1280,7 @@ int parse_uri(char* buf, int len, struct sip_uri* uri)
 			/* pn-purr */
 			param_switch(PN4_U, 'r', 'R', PN4_R);
 			param_switch(PN4_R, 'r', 'R', PN4_R2);
-			param_switch1(PN4_R2, '=', PN4_eq);
+			param_xswitch1(PN4_R2, '=', PN4_eq);
 			case PN4_eq:
 				param=&uri->pn_purr;
 				param_val=&uri->pn_purr_val;
diff --git a/parser/test/test_parser.c b/parser/test/test_parser.c
index 67833f01bfa..3a1d06b8b4b 100644
--- a/parser/test/test_parser.c
+++ b/parser/test/test_parser.c
@@ -82,19 +82,25 @@ void test_parse_uri(void)
 	in = *_str("sip:alice@atlanta.org;pn-prid=");
 	ok(parse_uri(in.s, in.len, &u) != 0, "puri-29");
 	in = *_str("sip:alice@atlanta.org;pn-prid");
-	ok(parse_uri(in.s, in.len, &u) != 0, "puri-30");
+	ok(parse_uri(in.s, in.len, &u) != 0, "puri-30-1");
+	in = *_str("sip:alice@atlanta.org;pn-prid;foo=bar");
+	ok(parse_uri(in.s, in.len, &u) != 0, "puri-30-2");
 
 	/* pn-param value is mandatory */
 	in = *_str("sip:alice@atlanta.org;pn-param=");
 	ok(parse_uri(in.s, in.len, &u) != 0, "puri-31");
 	in = *_str("sip:alice@atlanta.org;pn-param");
-	ok(parse_uri(in.s, in.len, &u) != 0, "puri-32");
+	ok(parse_uri(in.s, in.len, &u) != 0, "puri-32-1");
+	in = *_str("sip:alice@atlanta.org;pn-param;foo=bar");
+	ok(parse_uri(in.s, in.len, &u) != 0, "puri-32-2");
 
 	/* pn-purr value is mandatory */
 	in = *_str("sip:alice@atlanta.org;pn-purr=");
 	ok(parse_uri(in.s, in.len, &u) != 0, "puri-33");
 	in = *_str("sip:alice@atlanta.org;pn-purr");
-	ok(parse_uri(in.s, in.len, &u) != 0, "puri-34");
+	ok(parse_uri(in.s, in.len, &u) != 0, "puri-34-1");
+	in = *_str("sip:alice@atlanta.org;pn-purr;foo=bar");
+	ok(parse_uri(in.s, in.len, &u) != 0, "puri-34-2");
 
 	in = *_str("sip:alice@atlanta.org;pn-provider=x;pn-prid=y;"
 	                                 "pn-param=z;pn-purr=t");