diff --git a/pkg/rtc/participant.go b/pkg/rtc/participant.go
index 4de579399..d8d1b965d 100644
--- a/pkg/rtc/participant.go
+++ b/pkg/rtc/participant.go
@@ -4780,6 +4780,15 @@ func (p *ParticipantImpl) PerformRpc(req *livekit.PerformRpcRequest, resultCh ch
 			}
 		})
 
+		p.lock.RLock()
+		rtt := p.lastRTT
+		p.lock.RUnlock()
+
+		requestTimeout := responseTimeout
+		if rtt < requestTimeout {
+			requestTimeout -= rtt
+		}
+
 		rpcRequest := &livekit.DataPacket{
 			Kind:                livekit.DataPacket_RELIABLE,
 			ParticipantIdentity: id,
@@ -4788,7 +4797,7 @@ func (p *ParticipantImpl) PerformRpc(req *livekit.PerformRpcRequest, resultCh ch
 					Id:                id,
 					Method:            req.GetMethod(),
 					Payload:           req.GetPayload(),
-					ResponseTimeoutMs: responseTimeout - p.lastRTT,
+					ResponseTimeoutMs: requestTimeout,
 					Version:           1,
 				},
 			},
diff --git a/pkg/rtc/participant_internal_test.go b/pkg/rtc/participant_internal_test.go
index 2e88c1c54..17d85c477 100644
--- a/pkg/rtc/participant_internal_test.go
+++ b/pkg/rtc/participant_internal_test.go
@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"regexp"
 	"runtime"
+	"slices"
 	"strings"
 	"sync"
 	"testing"
@@ -1927,3 +1928,48 @@ func TestUpdateVideoTrackReachesQueuedReplacement(t *testing.T) {
 	require.NoError(t, p.UpdateVideoTrack(&livekit.UpdateLocalVideoTrack{TrackSid: sid, Width: 1280, Height: 720}))
 	require.EqualValues(t, 1280, p.pendingTracks[pendingTrackCid].trackInfos[0].Width)
 }
+
+// the response timeout forwarded to the callee is the caller's less the round trip, and must not
+// wrap around when the round trip is not below the timeout.
+func TestPerformRpcForwardedResponseTimeout(t *testing.T) {
+	cases := []struct {
+		name     string
+		timeout  uint32
+		rtt      uint32
+		expected uint32
+	}{
+		{"no rtt", 15000, 0, 15000},
+		{"rtt taken off", 15000, 150, 14850},
+		{"rtt just under the timeout", 1000, 999, 1},
+		{"rtt equal to the timeout", 1000, 1000, 1000},
+		{"rtt above the timeout", 1000, 1500, 1000},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			p := newParticipantForTest("test")
+			p.lock.Lock()
+			p.lastRTT = c.rtt
+			p.lock.Unlock()
+
+			errorCh := make(chan error, 2)
+			p.PerformRpc(&livekit.PerformRpcRequest{
+				DestinationIdentity: "test",
+				Method:              "method",
+				ResponseTimeoutMs:   c.timeout,
+			}, make(chan string, 1), errorCh)
+
+			// the reliable channel is not writable yet, so the request is held for when it opens
+			var held [][]byte
+			require.Eventually(t, func() bool {
+				p.reliableDataInfo.joiningMessageLock.Lock()
+				defer p.reliableDataInfo.joiningMessageLock.Unlock()
+				held = slices.Clone(p.reliableDataInfo.joiningUnsequencedMessages)
+				return len(held) == 1
+			}, time.Second, time.Millisecond)
+
+			dp := &livekit.DataPacket{}
+			require.NoError(t, proto.Unmarshal(held[0], dp))
+			require.Equal(t, c.expected, dp.GetRpcRequest().GetResponseTimeoutMs())
+		})
+	}
+}