diff --git a/lib/reg/rerrno.c b/lib/reg/rerrno.c
index 540fe304b91..e5633ed25f8 100644
--- a/lib/reg/rerrno.c
+++ b/lib/reg/rerrno.c
@@ -29,6 +29,8 @@ rerr_t rerrno;
 
 str error_info[] = {
 	{EI_R_FINE,       sizeof(EI_R_FINE) - 1},
+	{EI_R_INTERNAL,   sizeof(EI_R_INTERNAL) - 1},
+	{EI_R_NOT_IMPL,   sizeof(EI_R_NOT_IMPL) - 1},
 	{EI_R_UL_DEL_R,   sizeof(EI_R_UL_DEL_R) - 1},
 	{EI_R_UL_GET_R,   sizeof(EI_R_UL_GET_R) - 1},
 	{EI_R_UL_NEW_R,   sizeof(EI_R_UL_NEW_R) - 1},
@@ -62,6 +64,8 @@ str error_info[] = {
 
 int rerr_codes[] = {
 	200, /* R_FINE */
+	500, /* R_FINE */
+	501, /* R_FINE */
 	500, /* R_UL_DEL_R */
 	500, /* R_UL_GET */
 	500, /* R_UL_NEW_R */
diff --git a/lib/reg/rerrno.h b/lib/reg/rerrno.h
index dbae0cf3792..c913ed599c8 100644
--- a/lib/reg/rerrno.h
+++ b/lib/reg/rerrno.h
@@ -25,6 +25,8 @@
 #define __LIB_REG_RERRNO_H__
 
 #define EI_R_FINE       "No problem"                                /* R_FINE */
+#define EI_R_INTERNAL   "Server Internal Error"                     /* R_INTERNAL */
+#define EI_R_NOT_IMPL   "Method Not Implemented"                    /* R_NOT_IMPL */
 #define EI_R_UL_DEL_R   "usrloc_record_delete failed"               /* R_UL_DEL_R */
 #define EI_R_UL_GET_R   "usrloc_record_get failed"                  /* R_UL_GET */
 #define EI_R_UL_NEW_R   "usrloc_record_new failed"                  /* R_UL_NEW_R */
@@ -42,21 +44,23 @@
 #define EI_R_TO_MISS    "To header not found"                       /* R_TO_MISS */
 #define EI_R_CID_MISS   "Call-ID header not found"                  /* R_CID_MISS */
 #define EI_R_CS_MISS    "CSeq header not found"                     /* R_CS_MISS */
-#define EI_R_PARSE_EXP	"Expires parse error"                       /* R_PARSE_EXP */
+#define EI_R_PARSE_EXP  "Expires parse error"                       /* R_PARSE_EXP */
 #define EI_R_PARSE_CONT "Contact parse error"                       /* R_PARSE_CONT */
-#define EI_R_STAR_EXP	"* used in contact and expires is not zero" /* R_STAR__EXP */
-#define EI_R_STAR_CONT	"* used in contact and more than 1 contact" /* R_STAR_CONT */
-#define EI_R_OOO	"Out of order request"                      /* R_OOO */
-#define EI_R_RETRANS	"Retransmission"                            /* R_RETRANS */
+#define EI_R_STAR_EXP   "* used in contact and expires is not zero" /* R_STAR__EXP */
+#define EI_R_STAR_CONT  "* used in contact and more than 1 contact" /* R_STAR_CONT */
+#define EI_R_OOO        "Out of order request"                      /* R_OOO */
+#define EI_R_RETRANS    "Retransmission"                            /* R_RETRANS */
 #define EI_R_UNESCAPE   "Error while unescaping username"           /* R_UNESCAPE */
 #define EI_R_TOO_MANY   "Too many registered contacts"              /* R_TOO_MANY */
-#define EI_R_CONTACT_LEN  "Contact/received too long"               /* R_CONTACT_LEN */
+#define EI_R_CONTACT_LEN "Contact/received too long"                /* R_CONTACT_LEN */
 #define EI_R_CALLID_LEN  "Callid too long"                          /* R_CALLID_LEN */
 #define EI_R_PARSE_PATH  "Path parse error"                         /* R_PARSE_PATH */
 #define EI_R_PATH_UNSUP  "No support for found Path indicated"      /* R_PATH_UNSUP */
 
 typedef enum rerr {
 	R_FINE = 0,   /*!< Everything went OK */
+	R_INTERNAL,   /*!< Internal Error */
+	R_NOT_IMPL,   /*!< Not Implemented */
 	R_UL_DEL_R,   /*!< Usrloc record delete failed */
 	R_UL_GET_R,   /*!< Usrloc record get failed */
 	R_UL_NEW_R,   /*!< Usrloc new record failed */
diff --git a/modules/mid_registrar/save.c b/modules/mid_registrar/save.c
index ed819061b3f..43eede48b1d 100644
--- a/modules/mid_registrar/save.c
+++ b/modules/mid_registrar/save.c
@@ -2323,8 +2323,9 @@ int mid_reg_save(struct sip_msg *msg, char *dom, char *flags_gp,
 	int rc = -1, st, unlock_udomain = 0;
 
 	if (msg->REQ_METHOD != METHOD_REGISTER) {
-		LM_ERR("ignoring non-REGISTER SIP request (%d)\n", msg->REQ_METHOD);
-		return -1;
+		LM_ERR("rejecting non-REGISTER SIP request (%d)\n", msg->REQ_METHOD);
+		rerrno = R_NOT_IMPL;
+		goto out_error;
 	}
 
 	rerrno = R_FINE;
@@ -2343,7 +2344,7 @@ int mid_reg_save(struct sip_msg *msg, char *dom, char *flags_gp,
 
 	if (parse_reg_headers(msg) != 0) {
 		LM_ERR("failed to parse req headers\n");
-		return -1;
+		goto out_error;
 	}
 
 	if (!to_uri_gp) {
@@ -2362,7 +2363,7 @@ int mid_reg_save(struct sip_msg *msg, char *dom, char *flags_gp,
 
 	if (extract_aor(&to_uri, &sctx.aor, 0, 0) < 0) {
 		LM_ERR("failed to extract Address Of Record\n");
-		return -1;
+		goto out_error;
 	}
 
 	if (check_contacts(msg, &st) > 0) {
@@ -2383,7 +2384,8 @@ int mid_reg_save(struct sip_msg *msg, char *dom, char *flags_gp,
 			if (!del_lump(msg, path->name.s - msg->buf,
 			              path->len, HDR_PATH_T)) {
 				LM_ERR("failed to remove Path HF\n");
-				return -1;
+				rerrno = R_INTERNAL;
+				goto out_error;
 			}
 		}
 	}
diff --git a/modules/registrar/save.c b/modules/registrar/save.c
index 7fed5b62651..f854ec042dc 100644
--- a/modules/registrar/save.c
+++ b/modules/registrar/save.c
@@ -237,10 +237,12 @@ static inline int insert_contacts(struct sip_msg* _m, contact_t* _c,
 				if (r==NULL || r->contacts==NULL) {
 					LM_CRIT("BUG - overflow detected with r=%p and "
 						"contacts=%p\n",r,r->contacts);
+					rerrno = R_INTERNAL;
 					goto error;
 				}
 				if (ul.delete_ucontact( r, r->contacts, 0)!=0) {
 					LM_ERR("failed to remove contact\n");
+					rerrno = R_INTERNAL;
 					goto error;
 				}
 			} else {
@@ -649,6 +651,7 @@ int save_aux(struct sip_msg* _m, str* forced_binding, char* _d, char* _f, char*
 		if (parse_contacts(forced_binding, &forced_c) < 0) {
 			LM_ERR("Unable to parse forced binding [%.*s]\n",
 				forced_binding->len, forced_binding->s);
+			rerrno = R_INTERNAL;
 			goto error;
 		}
 		/* prevent processing all the headers from the message */