diff --git a/go.mod b/go.mod
index 65d34246ca..f693194c08 100644
--- a/go.mod
+++ b/go.mod
@@ -43,7 +43,7 @@ require (
 	github.com/sourcegraph/conc v0.3.0
 	github.com/spf13/cobra v1.8.1
 	github.com/ssvlabs/eth2-key-manager v1.5.6
-	github.com/ssvlabs/ssv-spec v1.2.3-0.20260121164943-4280751195c0
+	github.com/ssvlabs/ssv-spec v1.2.3-0.20260216165540-a5bc57233c10
 	github.com/ssvlabs/ssv/ssvsigner v0.0.0-20251110161756-cd931098ea44
 	github.com/status-im/keycard-go v0.2.0
 	github.com/stretchr/testify v1.11.1
diff --git a/go.sum b/go.sum
index f6f89bc610..9dc73f2407 100644
--- a/go.sum
+++ b/go.sum
@@ -731,8 +731,8 @@ github.com/ssvlabs/eth2-key-manager v1.5.6 h1:BMxVCsbcIlUiiO0hpePkHxzX0yhKgMkEzV
 github.com/ssvlabs/eth2-key-manager v1.5.6/go.mod h1:tjzhmMzrc0Lzc/OMW1h9Mz8AhmKH7FQC/nFiMNJ0bd8=
 github.com/ssvlabs/go-eth2-client v0.6.31-0.20250922150906-26179dd60c9c h1:iNQoRbEajriawtkSFiyHsJNiXyfyTrPrnmO0NaWiNv4=
 github.com/ssvlabs/go-eth2-client v0.6.31-0.20250922150906-26179dd60c9c/go.mod h1:fvULSL9WtNskkOB4i+Yyr6BKpNHXvmpGZj9969fCrfY=
-github.com/ssvlabs/ssv-spec v1.2.3-0.20260121164943-4280751195c0 h1:/sGLLm5PFr2FvfujnnwZvdB+8chUaJxbSIdKiQ5l/J0=
-github.com/ssvlabs/ssv-spec v1.2.3-0.20260121164943-4280751195c0/go.mod h1:GedhFYGHVJRYYH3nEp05Gn14tyvg6VbTbaIxrMtI7Cg=
+github.com/ssvlabs/ssv-spec v1.2.3-0.20260216165540-a5bc57233c10 h1:ecHp7F0mcvc9AKCb00PEX2CGgxraUvhkARN+XheiD3o=
+github.com/ssvlabs/ssv-spec v1.2.3-0.20260216165540-a5bc57233c10/go.mod h1:GedhFYGHVJRYYH3nEp05Gn14tyvg6VbTbaIxrMtI7Cg=
 github.com/ssvlabs/ssv/ssvsigner v0.0.0-20251110161756-cd931098ea44 h1:uwOEN9S5D+CQcD1AC/XKeQpfb3AVXe1SJ4hhhIJhojU=
 github.com/ssvlabs/ssv/ssvsigner v0.0.0-20251110161756-cd931098ea44/go.mod h1:w7i5oZKhFVq9jVOTe1Ykk0CtJEtmSJbdXErIbsewMXk=
 github.com/status-im/keycard-go v0.2.0 h1:QDLFswOQu1r5jsycloeQh3bVU8n/NatHHaZobtDnDzA=
diff --git a/protocol/v2/ssv/runner/aggregator_committee.go b/protocol/v2/ssv/runner/aggregator_committee.go
index 9d7c56c760..5851cb224b 100644
--- a/protocol/v2/ssv/runner/aggregator_committee.go
+++ b/protocol/v2/ssv/runner/aggregator_committee.go
@@ -1592,8 +1592,14 @@ func (r *AggregatorCommitteeRunner) executeDuty(ctx context.Context, logger *zap
 
 		case spectypes.BNRoleSyncCommitteeContribution:
 			// Sign sync committee selection proofs for each subcommittee
+			// Selection proof depends only on slot+subcommittee index, so emit at most one per subnet.
+			seenSubnets := make(map[uint64]struct{})
 			for _, index := range vDuty.ValidatorSyncCommitteeIndices {
 				subnet := r.GetBeaconNode().SyncCommitteeSubnetID(phase0.CommitteeIndex(index))
+				if _, seen := seenSubnets[subnet]; seen {
+					continue
+				}
+				seenSubnets[subnet] = struct{}{}
 
 				data := &altair.SyncAggregatorSelectionData{
 					Slot:              duty.DutySlot(),
diff --git a/ssvsigner/go.mod b/ssvsigner/go.mod
index c3530f4185..7e874126eb 100644
--- a/ssvsigner/go.mod
+++ b/ssvsigner/go.mod
@@ -33,7 +33,7 @@ require (
 	github.com/sourcegraph/conc v0.3.0
 	github.com/ssvlabs/eth2-key-manager v1.5.6
 	github.com/ssvlabs/ssv v1.2.1-0.20251110161756-cd931098ea44
-	github.com/ssvlabs/ssv-spec v1.2.3-0.20260121164943-4280751195c0
+	github.com/ssvlabs/ssv-spec v1.2.3-0.20260216165540-a5bc57233c10
 	github.com/stretchr/testify v1.11.1
 	github.com/testcontainers/testcontainers-go v0.37.0
 	github.com/valyala/fasthttp v1.58.0
diff --git a/ssvsigner/go.sum b/ssvsigner/go.sum
index bbb593a014..27b465e5f8 100644
--- a/ssvsigner/go.sum
+++ b/ssvsigner/go.sum
@@ -332,8 +332,8 @@ github.com/spaolacci/murmur3 v1.1.0 h1:7c1g84S4BPRrfL5Xrdp6fOJ206sU9y293DDHaoy0b
 github.com/spaolacci/murmur3 v1.1.0/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/ssvlabs/eth2-key-manager v1.5.6 h1:BMxVCsbcIlUiiO0hpePkHxzX0yhKgMkEzVSoNmSXySM=
 github.com/ssvlabs/eth2-key-manager v1.5.6/go.mod h1:tjzhmMzrc0Lzc/OMW1h9Mz8AhmKH7FQC/nFiMNJ0bd8=
-github.com/ssvlabs/ssv-spec v1.2.3-0.20260121164943-4280751195c0 h1:/sGLLm5PFr2FvfujnnwZvdB+8chUaJxbSIdKiQ5l/J0=
-github.com/ssvlabs/ssv-spec v1.2.3-0.20260121164943-4280751195c0/go.mod h1:GedhFYGHVJRYYH3nEp05Gn14tyvg6VbTbaIxrMtI7Cg=
+github.com/ssvlabs/ssv-spec v1.2.3-0.20260216165540-a5bc57233c10 h1:ecHp7F0mcvc9AKCb00PEX2CGgxraUvhkARN+XheiD3o=
+github.com/ssvlabs/ssv-spec v1.2.3-0.20260216165540-a5bc57233c10/go.mod h1:GedhFYGHVJRYYH3nEp05Gn14tyvg6VbTbaIxrMtI7Cg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=