diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 78dddda2dc..b149c99c6a 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -4333,7 +4333,7 @@ void sip_scheddestroy(struct sip_pvt *p, int ms)
 	}
 	p->autokillid = ast_sched_add(sched, ms, __sip_autodestruct, dialog_ref(p, "setting ref as passing into ast_sched_add for __sip_autodestruct"));
 
-	if (p->stimer && p->stimer->st_active == TRUE && p->stimer->st_schedid > 0) {
+	if (p->stimer && p->stimer->st_active == TRUE && p->stimer->st_schedid > -1) {
 		stop_session_timer(p);
 	}
 }
@@ -22595,7 +22595,7 @@ static void check_pendings(struct sip_pvt *p)
 		sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
 	} else if (ast_test_flag(&p->flags[0], SIP_NEEDREINVITE)) {
 		/* if we can't REINVITE, hold it for later */
-		if (p->pendinginvite || p->invitestate == INV_CALLING || p->invitestate == INV_PROCEEDING || p->invitestate == INV_EARLY_MEDIA || p->waitid > 0) {
+		if (p->pendinginvite || p->invitestate == INV_CALLING || p->invitestate == INV_PROCEEDING || p->invitestate == INV_EARLY_MEDIA || p->waitid > -1) {
 			ast_debug(2, "NOT Sending pending reinvite (yet) on '%s'\n", p->callid);
 		} else {
 			ast_debug(2, "Sending pending reinvite on '%s'\n", p->callid);
diff --git a/channels/chan_skinny.c b/channels/chan_skinny.c
index ef1fda2e59..9462eb685c 100644
--- a/channels/chan_skinny.c
+++ b/channels/chan_skinny.c
@@ -4332,7 +4332,7 @@ static int skinny_dialer_cb(const void *data)
 {
 	struct skinny_subchannel *sub = (struct skinny_subchannel *)data;
 	SKINNY_DEBUG(DEBUG_SUB, 3, "Sub %u - Dialer called from SCHED %d\n", sub->callid, sub->dialer_sched);
-	sub->dialer_sched = 0;
+	sub->dialer_sched = -1;
 	skinny_dialer(sub, 1);
 	return 0;
 }
@@ -4340,7 +4340,7 @@ static int skinny_dialer_cb(const void *data)
 static int skinny_autoanswer_cb(const void *data)
 {
 	struct skinny_subchannel *sub = (struct skinny_subchannel *)data;
-	sub->aa_sched = 0;
+	sub->aa_sched = -1;
 	setsubstate(sub, SKINNY_CONNECTED);
 	return 0;
 }
@@ -4379,7 +4379,7 @@ static int skinny_call(struct ast_channel *ast, const char *dest, int timeout)
 
 	AST_LIST_TRAVERSE(ast_channel_varshead(ast), current, entries) {
 		if (!(strcasecmp(ast_var_name(current),"SKINNY_AUTOANSWER"))) {
-			if (d->hookstate == SKINNY_ONHOOK && !sub->aa_sched) {
+			if (d->hookstate == SKINNY_ONHOOK && !sub->aa_sched < 0) {
 				char buf[24];
 				int aatime;
 				char *stringp = buf, *curstr;
@@ -4841,8 +4841,8 @@ static struct ast_channel *skinny_new(struct skinny_line *l, struct skinny_subli
 			sub->xferor = 0;
 			sub->related = NULL;
 			sub->calldirection = direction;
-			sub->aa_sched = 0;
-			sub->dialer_sched = 0;
+			sub->aa_sched = -1;
+			sub->dialer_sched = -1;
 
 			if (subline) {
 				sub->subline = subline;
@@ -4983,12 +4983,12 @@ static void setsubstate(struct skinny_subchannel *sub, int state)
 
 	if (sub->dialer_sched) {
 		skinny_sched_del(sub->dialer_sched, sub);
-		sub->dialer_sched = 0;
+		sub->dialer_sched = -1;
 	}
 
 	if (state != SUBSTATE_RINGIN && sub->aa_sched) {
 		skinny_sched_del(sub->aa_sched, sub);
-		sub->aa_sched = 0;
+		sub->aa_sched = -1;
 		sub->aa_beep = 0;
 		sub->aa_mute = 0;
 	}
@@ -5642,7 +5642,7 @@ static int handle_keypad_button_message(struct skinny_req *req, struct skinnyses
 	if ((sub->owner && ast_channel_state(sub->owner) <  AST_STATE_UP)) {
 		if (sub->dialer_sched &&	!skinny_sched_del(sub->dialer_sched, sub)) {
 			SKINNY_DEBUG(DEBUG_SUB, 3, "Sub %u - Got a digit and not timed out, so try dialing\n", sub->callid);
-			sub->dialer_sched = 0;
+			sub->dialer_sched = -1;
 			len = strlen(sub->exten);
 			if (len == 0) {
 				transmit_stop_tone(d, l->instance, sub->callid);
@@ -6526,7 +6526,7 @@ static int handle_soft_key_event_message(struct skinny_req *req, struct skinnyse
 			d->name, instance, callreference);
 		if (sub->dialer_sched && !skinny_sched_del(sub->dialer_sched, sub)) {
 			size_t len;
-			sub->dialer_sched = 0;
+			sub->dialer_sched = -1;
 			len = strlen(sub->exten);
 			if (len > 0) {
 				sub->exten[len-1] = '\0';
diff --git a/res/res_rtp_asterisk.c b/res/res_rtp_asterisk.c
index fcbc12ea83..452f7895f1 100644
--- a/res/res_rtp_asterisk.c
+++ b/res/res_rtp_asterisk.c
@@ -3278,7 +3278,7 @@ static int ast_rtp_raw_write(struct ast_rtp_instance *instance, struct ast_frame
 			rtp->txcount++;
 			rtp->txoctetcount += (res - hdrlen);
 
-			if (rtp->rtcp && rtp->rtcp->schedid < 1) {
+			if (rtp->rtcp && rtp->rtcp->schedid < 0) {
 				ast_debug(1, "Starting RTCP transmission on RTP instance '%p'\n", instance);
 				ao2_ref(instance, +1);
 				rtp->rtcp->schedid = ast_sched_add(rtp->sched, ast_rtcp_calc_interval(rtp), ast_rtcp_write, instance);
@@ -4397,7 +4397,7 @@ static struct ast_frame *ast_rtp_read(struct ast_rtp_instance *instance, int rtc
 	}
 
 	/* Do not schedule RR if RTCP isn't run */
-	if (rtp->rtcp && !ast_sockaddr_isnull(&rtp->rtcp->them) && rtp->rtcp->schedid < 1) {
+	if (rtp->rtcp && !ast_sockaddr_isnull(&rtp->rtcp->them) && rtp->rtcp->schedid < 0) {
 		/* Schedule transmission of Receiver Report */
 		ao2_ref(instance, +1);
 		rtp->rtcp->schedid = ast_sched_add(rtp->sched, ast_rtcp_calc_interval(rtp), ast_rtcp_write, instance);