diff --git a/beacon_chain/nimbus_beacon_node.nim b/beacon_chain/nimbus_beacon_node.nim
index ecfa5ba51d..6d10b9ef77 100644
--- a/beacon_chain/nimbus_beacon_node.nim
+++ b/beacon_chain/nimbus_beacon_node.nim
@@ -1295,15 +1295,22 @@ proc addCapellaMessageHandlers(
   node.addAltairMessageHandlers(forkDigest, slot)
   node.network.subscribe(getBlsToExecutionChangeTopic(forkDigest), basicParams)
 
-proc addDenebMessageHandlers(
-    node: BeaconNode, forkDigest: ForkDigest, slot: Slot) =
+proc doAddDenebMessageHandlers(
+    node: BeaconNode, forkDigest: ForkDigest, slot: Slot,
+    blobSidecarSubnetCount: uint64) =
   node.addCapellaMessageHandlers(forkDigest, slot)
-  for topic in blobSidecarTopics(forkDigest):
+  for topic in blobSidecarTopics(forkDigest, blobSidecarSubnetCount):
     node.network.subscribe(topic, basicParams)
 
+proc addDenebMessageHandlers(
+    node: BeaconNode, forkDigest: ForkDigest, slot: Slot) =
+  node.doAddDenebMessageHandlers(
+    forkDigest, slot, node.dag.cfg.BLOB_SIDECAR_SUBNET_COUNT)
+
 proc addElectraMessageHandlers(
     node: BeaconNode, forkDigest: ForkDigest, slot: Slot) =
-  node.addDenebMessageHandlers(forkDigest, slot)
+  node.doAddDenebMessageHandlers(
+    forkDigest, slot, node.dag.cfg.BLOB_SIDECAR_SUBNET_COUNT_ELECTRA)
 
 proc addFuluMessageHandlers(
     node: BeaconNode, forkDigest: ForkDigest, slot: Slot) =
@@ -1324,13 +1331,19 @@ proc removeCapellaMessageHandlers(node: BeaconNode, forkDigest: ForkDigest) =
   node.removeAltairMessageHandlers(forkDigest)
   node.network.unsubscribe(getBlsToExecutionChangeTopic(forkDigest))
 
-proc removeDenebMessageHandlers(node: BeaconNode, forkDigest: ForkDigest) =
+proc doRemoveDenebMessageHandlers(
+    node: BeaconNode, forkDigest: ForkDigest, blobSidecarSubnetCount: uint64) =
   node.removeCapellaMessageHandlers(forkDigest)
-  for topic in blobSidecarTopics(forkDigest):
+  for topic in blobSidecarTopics(forkDigest, blobSidecarSubnetCount):
     node.network.unsubscribe(topic)
 
+proc removeDenebMessageHandlers(node: BeaconNode, forkDigest: ForkDigest) =
+  node.doRemoveDenebMessageHandlers(
+    forkDigest, node.dag.cfg.BLOB_SIDECAR_SUBNET_COUNT)
+
 proc removeElectraMessageHandlers(node: BeaconNode, forkDigest: ForkDigest) =
-  node.removeDenebMessageHandlers(forkDigest)
+  node.doRemoveDenebMessageHandlers(
+    forkDigest, node.dag.cfg.BLOB_SIDECAR_SUBNET_COUNT_ELECTRA)
 
 proc removeFuluMessageHandlers(node: BeaconNode, forkDigest: ForkDigest) =
   node.removeElectraMessageHandlers(forkDigest)
@@ -2083,7 +2096,12 @@ proc installMessageValidators(node: BeaconNode) =
       when consensusFork >= ConsensusFork.Deneb:
         # blob_sidecar_{subnet_id}
         # https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.5/specs/deneb/p2p-interface.md#blob_sidecar_subnet_id
-        for it in BlobId:
+        let subnetCount =
+          when consensusFork >= ConsensusFork.Electra:
+            node.dag.cfg.BLOB_SIDECAR_SUBNET_COUNT_ELECTRA
+          else:
+            node.dag.cfg.BLOB_SIDECAR_SUBNET_COUNT
+        for it in 0.BlobId ..< subnetCount.BlobId:
           closureScope:  # Needed for inner `proc`; don't lift it out of loop.
             let subnet_id = it
             node.network.addValidator(
diff --git a/beacon_chain/spec/datatypes/base.nim b/beacon_chain/spec/datatypes/base.nim
index a4bcf6940e..a2f1225370 100644
--- a/beacon_chain/spec/datatypes/base.nim
+++ b/beacon_chain/spec/datatypes/base.nim
@@ -201,7 +201,7 @@ type
 
   BlobId* = distinct uint8
     ## The blob id maps which gossip subscription to use to publish a
-    ## blob sidecar - it is distinct from the CommitteeIndex in particular
+    ## blob sidecar - it is distinct from the BlobIndex in particular
     ##
     ## The `BlobId` type is constrained to values in the range
     ## `[0, MAX_BLOBS_PER_BLOCK_ELECTRA)` during initialization.
diff --git a/beacon_chain/spec/network.nim b/beacon_chain/spec/network.nim
index 62bc1b9e36..9c61761122 100644
--- a/beacon_chain/spec/network.nim
+++ b/beacon_chain/spec/network.nim
@@ -118,7 +118,7 @@ func compute_subnet_for_blob_sidecar*(
     if slot >= cfg.ELECTRA_FORK_EPOCH.start_slot:
       cfg.BLOB_SIDECAR_SUBNET_COUNT_ELECTRA
     else:
-      BLOB_SIDECAR_SUBNET_COUNT
+      cfg.BLOB_SIDECAR_SUBNET_COUNT
   BlobId(blob_index mod subnetCount)
 
 # https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.10/specs/fulu/p2p-interface.md#compute_subnet_for_data_column_sidecar
@@ -243,8 +243,9 @@ func getSyncSubnets*(
     res.setBit(i div (SYNC_COMMITTEE_SIZE div SYNC_COMMITTEE_SUBNET_COUNT))
   res
 
-iterator blobSidecarTopics*(forkDigest: ForkDigest): string =
-  for subnet_id in BlobId:
+iterator blobSidecarTopics*(
+    forkDigest: ForkDigest, subnetCount: uint64): string =
+  for subnet_id in 0.BlobId ..< subnetCount.BlobId:
     yield getBlobSidecarTopic(forkDigest, subnet_id)
 
 # https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.10/specs/fulu/p2p-interface.md#data_column_sidecar_subnet_id
diff --git a/tests/test_honest_validator.nim b/tests/test_honest_validator.nim
index 59b79d9bba..e7fa1b6c39 100644
--- a/tests/test_honest_validator.nim
+++ b/tests/test_honest_validator.nim
@@ -1,5 +1,5 @@
 # beacon_chain
-# Copyright (c) 2020-2024 Status Research & Development GmbH
+# Copyright (c) 2020-2025 Status Research & Development GmbH
 # Licensed and distributed under either of
 #   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
 #   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
@@ -80,7 +80,7 @@ suite "Honest validator":
         "/eth2/00000000/sync_committee_3/ssz_snappy"
       getBlobSidecarTopic(forkDigest, BlobId(1)) ==
         "/eth2/00000000/blob_sidecar_1/ssz_snappy"
-      toSeq(blobSidecarTopics(forkDigest)) ==
+      toSeq(blobSidecarTopics(forkDigest, subnetCount = 9)) ==
         ["/eth2/00000000/blob_sidecar_0/ssz_snappy",
          "/eth2/00000000/blob_sidecar_1/ssz_snappy",
          "/eth2/00000000/blob_sidecar_2/ssz_snappy",