diff --git a/Dockerfile b/Dockerfile
index 049b59d7..74c44127 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -90,6 +90,7 @@ ENV VPNSP=pia \
     FIREWALL=on \
     EXTRA_SUBNETS= \
     FIREWALL_VPN_INPUT_PORTS= \
+    FIREWALL_INPUT_PORTS= \
     FIREWALL_DEBUG=off \
     # Tinyproxy
     TINYPROXY=off \
diff --git a/README.md b/README.md
index af71a656..0f2b2774 100644
--- a/README.md
+++ b/README.md
@@ -225,6 +225,7 @@ That one is important if you want to connect to the container from your LAN for
 | `FIREWALL` | `on` | `on` or `off` | Turn on or off the container built-in firewall. You should use it for **debugging purposes** only. |
 | `EXTRA_SUBNETS` | | i.e. `192.168.1.0/24,192.168.10.121,10.0.0.5/28` | Comma separated subnets allowed in the container firewall |
 | `FIREWALL_VPN_INPUT_PORTS` | | i.e. `1000,8080` | Comma separated list of ports to allow from the VPN server side (useful for **vyprvpn** port forwarding) |
+| `FIREWALL_INPUT_PORTS` | | i.e. `1000,8000` | Comma separated list of ports to allow through the default interface. This seems needed for Kubernetes sidecars. |
 | `FIREWALL_DEBUG` | `off` | `on` or `off` | Prints every firewall related command. You should use it for **debugging purposes** only. |
 
 ### Shadowsocks
diff --git a/cmd/gluetun/main.go b/cmd/gluetun/main.go
index 4348c36d..55fd2b45 100644
--- a/cmd/gluetun/main.go
+++ b/cmd/gluetun/main.go
@@ -186,6 +186,14 @@ func _main(background context.Context, args []string) int { //nolint:gocognit,go
 		}
 	}
 
+	for _, port := range allSettings.Firewall.InputPorts {
+		err = firewallConf.SetAllowedPort(ctx, port, defaultInterface)
+		if err != nil {
+			logger.Error(err)
+			return 1
+		}
+	}
+
 	wg := &sync.WaitGroup{}
 
 	go collectStreamLines(ctx, streamMerger, logger, signalTunnelReady)
diff --git a/internal/params/firewall.go b/internal/params/firewall.go
index 665c1124..a25a5882 100644
--- a/internal/params/firewall.go
+++ b/internal/params/firewall.go
@@ -60,6 +60,30 @@ func (r *reader) GetVPNInputPorts() (ports []uint16, err error) {
 	return ports, nil
 }
 
+// GetInputPorts obtains a list of input ports to allow through the
+// default interface in the firewall, from the environment variable FIREWALL_INPUT_PORTS
+func (r *reader) GetInputPorts() (ports []uint16, err error) {
+	s, err := r.envParams.GetEnv("FIREWALL_INPUT_PORTS", libparams.Default(""))
+	if err != nil {
+		return nil, err
+	}
+	if len(s) == 0 {
+		return nil, nil
+	}
+	portsStr := strings.Split(s, ",")
+	ports = make([]uint16, len(portsStr))
+	for i := range portsStr {
+		portInt, err := strconv.Atoi(portsStr[i])
+		if err != nil {
+			return nil, fmt.Errorf("Input port %q is not valid (%s)", portInt, err)
+		} else if portInt <= 0 || portInt > 65535 {
+			return nil, fmt.Errorf("Input port %d must be between 1 and 65535", portInt)
+		}
+		ports[i] = uint16(portInt)
+	}
+	return ports, nil
+}
+
 // GetFirewallDebug obtains if the firewall should run in debug verbose mode from the environment variable FIREWALL_DEBUG
 func (r *reader) GetFirewallDebug() (debug bool, err error) {
 	return r.envParams.GetOnOff("FIREWALL_DEBUG", libparams.Default("off"))
diff --git a/internal/params/params.go b/internal/params/params.go
index beb13ccb..4fbccf7c 100644
--- a/internal/params/params.go
+++ b/internal/params/params.go
@@ -43,6 +43,7 @@ type Reader interface {
 	GetFirewall() (enabled bool, err error)
 	GetExtraSubnets() (extraSubnets []net.IPNet, err error)
 	GetVPNInputPorts() (ports []uint16, err error)
+	GetInputPorts() (ports []uint16, err error)
 	GetFirewallDebug() (debug bool, err error)
 
 	// VPN getters
diff --git a/internal/settings/firewall.go b/internal/settings/firewall.go
index bd8026dd..661e0077 100644
--- a/internal/settings/firewall.go
+++ b/internal/settings/firewall.go
@@ -12,6 +12,7 @@ import (
 type Firewall struct {
 	AllowedSubnets []net.IPNet
 	VPNInputPorts  []uint16
+	InputPorts     []uint16
 	Enabled        bool
 	Debug          bool
 }
@@ -28,11 +29,16 @@ func (f *Firewall) String() string {
 	for i, port := range f.VPNInputPorts {
 		vpnInputPorts[i] = fmt.Sprintf("%d", port)
 	}
+	inputPorts := make([]string, len(f.InputPorts))
+	for i, port := range f.InputPorts {
+		inputPorts[i] = fmt.Sprintf("%d", port)
+	}
 
 	settingsList := []string{
 		"Firewall settings:",
 		"Allowed subnets: " + strings.Join(allowedSubnets, ", "),
 		"VPN input ports: " + strings.Join(vpnInputPorts, ", "),
+		"Input ports: " + strings.Join(inputPorts, ", "),
 	}
 	if f.Debug {
 		settingsList = append(settingsList, "Debug: on")
@@ -50,6 +56,10 @@ func GetFirewallSettings(paramsReader params.Reader) (settings Firewall, err err
 	if err != nil {
 		return settings, err
 	}
+	settings.InputPorts, err = paramsReader.GetInputPorts()
+	if err != nil {
+		return settings, err
+	}
 	settings.Enabled, err = paramsReader.GetFirewall()
 	if err != nil {
 		return settings, err