diff --git a/src/devices/adsl/nm-device-adsl.c b/src/devices/adsl/nm-device-adsl.c
index a5b6641abf..d1d0a9b0de 100644
--- a/src/devices/adsl/nm-device-adsl.c
+++ b/src/devices/adsl/nm-device-adsl.c
@@ -477,7 +477,7 @@ act_stage3_ip4_config_start (NMDevice *device,
 	}
 
 	priv->ppp_manager = nm_ppp_manager_new (ppp_iface);
-	if (nm_ppp_manager_start (priv->ppp_manager, req, nm_setting_adsl_get_username (s_adsl), 30, &err)) {
+	if (nm_ppp_manager_start (priv->ppp_manager, req, nm_setting_adsl_get_username (s_adsl), 30, 0, &err)) {
 		g_signal_connect (priv->ppp_manager, NM_PPP_MANAGER_STATE_CHANGED,
 		                  G_CALLBACK (ppp_state_changed),
 		                  self);
diff --git a/src/devices/nm-device-ethernet.c b/src/devices/nm-device-ethernet.c
index fd80a607a2..3604a168a8 100644
--- a/src/devices/nm-device-ethernet.c
+++ b/src/devices/nm-device-ethernet.c
@@ -937,7 +937,7 @@ pppoe_stage3_ip4_config_start (NMDeviceEthernet *self, NMDeviceStateReason *reas
 	g_assert (s_pppoe);
 
 	priv->ppp_manager = nm_ppp_manager_new (nm_device_get_iface (NM_DEVICE (self)));
-	if (nm_ppp_manager_start (priv->ppp_manager, req, nm_setting_pppoe_get_username (s_pppoe), 30, &err)) {
+	if (nm_ppp_manager_start (priv->ppp_manager, req, nm_setting_pppoe_get_username (s_pppoe), 30, 0, &err)) {
 		g_signal_connect (priv->ppp_manager, NM_PPP_MANAGER_STATE_CHANGED,
 		                  G_CALLBACK (ppp_state_changed),
 		                  self);
diff --git a/src/devices/wwan/nm-modem.c b/src/devices/wwan/nm-modem.c
index d5f12b1cc2..9897424466 100644
--- a/src/devices/wwan/nm-modem.c
+++ b/src/devices/wwan/nm-modem.c
@@ -23,7 +23,9 @@
 
 #include "nm-modem.h"
 
+#include <fcntl.h>
 #include <string.h>
+#include <termios.h>
 
 #include "nm-core-internal.h"
 #include "nm-platform.h"
@@ -492,6 +494,23 @@ ppp_stats (NMPPPManager *ppp_manager,
 	}
 }
 
+static gboolean
+port_speed_is_zero (const char *port)
+{
+    struct termios options;
+    gs_fd_close int fd = -1;
+
+    fd = open (port, O_RDWR | O_NONBLOCK | O_NOCTTY);
+    if (fd < 0)
+		return FALSE;
+
+    memset (&options, 0, sizeof (struct termios));
+    if (tcgetattr (fd, &options) != 0)
+        return FALSE;
+
+    return cfgetospeed (&options) == B0;
+}
+
 static NMActStageReturn
 ppp_stage3_ip_config_start (NMModem *self,
                             NMActRequest *req,
@@ -502,6 +521,7 @@ ppp_stage3_ip_config_start (NMModem *self,
 	GError *error = NULL;
 	NMActStageReturn ret;
 	guint ip_timeout = 30;
+	guint baud_override = 0;
 
 	g_return_val_if_fail (NM_IS_MODEM (self), NM_ACT_STAGE_RETURN_FAILURE);
 	g_return_val_if_fail (NM_IS_ACT_REQUEST (req), NM_ACT_STAGE_RETURN_FAILURE);
@@ -531,8 +551,16 @@ ppp_stage3_ip_config_start (NMModem *self,
 		ip_timeout = priv->mm_ip_timeout;
 	}
 
+	/* Some tty drivers and modems ignore port speed, but pppd requires the
+	 * port speed to be > 0 or it exits. If the port speed is 0 pass an
+	 * explicit speed to pppd to prevent the exit.
+	 * https://bugzilla.redhat.com/show_bug.cgi?id=1281731
+	 */
+	if (port_speed_is_zero (priv->data_port))
+		baud_override = 57600;
+
 	priv->ppp_manager = nm_ppp_manager_new (priv->data_port);
-	if (nm_ppp_manager_start (priv->ppp_manager, req, ppp_name, ip_timeout, &error)) {
+	if (nm_ppp_manager_start (priv->ppp_manager, req, ppp_name, ip_timeout, baud_override, &error)) {
 		g_signal_connect (priv->ppp_manager, NM_PPP_MANAGER_STATE_CHANGED,
 		                  G_CALLBACK (ppp_state_changed),
 		                  self);
diff --git a/src/ppp-manager/nm-ppp-manager.c b/src/ppp-manager/nm-ppp-manager.c
index 0f0b9a5939..1db2a794a3 100644
--- a/src/ppp-manager/nm-ppp-manager.c
+++ b/src/ppp-manager/nm-ppp-manager.c
@@ -707,6 +707,7 @@ create_pppd_cmd_line (NMPPPManager *self,
                       NMSettingPppoe *pppoe,
                       NMSettingAdsl  *adsl,
                       const char *ppp_name,
+                      guint baud_override,
                       GError **err)
 {
 	NMPPPManagerPrivate *priv = NM_PPP_MANAGER_GET_PRIVATE (self);
@@ -798,6 +799,8 @@ create_pppd_cmd_line (NMPPPManager *self,
 
 	if (nm_setting_ppp_get_baud (setting))
 		nm_cmd_line_add_int (cmd, nm_setting_ppp_get_baud (setting));
+	else if (baud_override)
+		nm_cmd_line_add_int (cmd, (int) baud_override);
 
 	/* noauth by default, because we certainly don't have any information
 	 * with which to verify anything the peer gives us if we ask it to
@@ -896,6 +899,7 @@ nm_ppp_manager_start (NMPPPManager *manager,
                       NMActRequest *req,
                       const char *ppp_name,
                       guint32 timeout_secs,
+                      guint baud_override,
                       GError **err)
 {
 	NMPPPManagerPrivate *priv;
@@ -949,7 +953,7 @@ nm_ppp_manager_start (NMPPPManager *manager,
 
 	adsl_setting = (NMSettingAdsl *) nm_connection_get_setting (connection, NM_TYPE_SETTING_ADSL);
 
-	ppp_cmd = create_pppd_cmd_line (manager, s_ppp, pppoe_setting, adsl_setting, ppp_name, err);
+	ppp_cmd = create_pppd_cmd_line (manager, s_ppp, pppoe_setting, adsl_setting, ppp_name, baud_override, err);
 	if (!ppp_cmd)
 		goto out;
 
diff --git a/src/ppp-manager/nm-ppp-manager.h b/src/ppp-manager/nm-ppp-manager.h
index da1fdb5539..12748176a3 100644
--- a/src/ppp-manager/nm-ppp-manager.h
+++ b/src/ppp-manager/nm-ppp-manager.h
@@ -44,6 +44,7 @@ gboolean nm_ppp_manager_start (NMPPPManager *manager,
                                NMActRequest *req,
                                const char *ppp_name,
                                guint32 timeout_secs,
+                               guint baud_override,
                                GError **err);
 
 void     nm_ppp_manager_stop        (NMPPPManager *manager,