diff --git a/handshake/connection_parameters_manager.go b/handshake/connection_parameters_manager.go
index cef9abdeb..697670f62 100644
--- a/handshake/connection_parameters_manager.go
+++ b/handshake/connection_parameters_manager.go
@@ -5,6 +5,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"sync"
+	"time"
 
 	"github.com/lucas-clemente/quic-go/protocol"
 )
@@ -76,3 +77,16 @@ func (h *ConnectionParametersManager) GetStreamFlowControlWindow() (protocol.Byt
 
 	return protocol.ByteCount(value), nil
 }
+
+// GetIdleConnectionStateLifetime gets the idle timeout
+func (h *ConnectionParametersManager) GetIdleConnectionStateLifetime() (time.Duration, error) {
+	rawValue, err := h.GetRawValue(TagICSL)
+	if err != nil {
+		return 0, err
+	}
+
+	if len(rawValue) != 4 {
+		return 0, errors.New("expected uint32 for ICSL")
+	}
+	return time.Duration(binary.LittleEndian.Uint32(rawValue)) * time.Second, nil
+}
diff --git a/handshake/connection_parameters_manager_test.go b/handshake/connection_parameters_manager_test.go
index 2b8a44fbf..a1c7c6750 100644
--- a/handshake/connection_parameters_manager_test.go
+++ b/handshake/connection_parameters_manager_test.go
@@ -1,6 +1,8 @@
 package handshake
 
 import (
+	"time"
+
 	"github.com/lucas-clemente/quic-go/protocol"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -57,4 +59,11 @@ var _ = Describe("ConnectionsParameterManager", func() {
 			Expect(val).To(Equal(protocol.ByteCount(0xEFBEADDE)))
 		})
 	})
+
+	It("gets idle connection state lifetime", func() {
+		cpm.params[TagICSL] = []byte{0xad, 0xfb, 0xca, 0xde}
+		val, err := cpm.GetIdleConnectionStateLifetime()
+		Expect(err).ToNot(HaveOccurred())
+		Expect(val).To(Equal(0xdecafbad * time.Second))
+	})
 })