diff --git a/Cargo.lock b/Cargo.lock
index 013752d30..b3983b23b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1070,7 +1070,7 @@ dependencies = [
 [[package]]
 name = "enr"
 version = "0.1.0-alpha.3"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "base64 0.12.0",
  "bs58 0.3.0",
@@ -2032,7 +2032,7 @@ dependencies = [
 [[package]]
 name = "libp2p"
 version = "0.13.2"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "bytes",
  "futures",
@@ -2071,7 +2071,7 @@ dependencies = [
 [[package]]
 name = "libp2p-core"
 version = "0.13.2"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "asn1_der",
  "bs58 0.3.0",
@@ -2106,7 +2106,7 @@ dependencies = [
 [[package]]
 name = "libp2p-core-derive"
 version = "0.13.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "quote 1.0.3",
  "syn 1.0.17",
@@ -2115,7 +2115,7 @@ dependencies = [
 [[package]]
 name = "libp2p-deflate"
 version = "0.5.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "flate2",
  "futures",
@@ -2126,7 +2126,7 @@ dependencies = [
 [[package]]
 name = "libp2p-discv5"
 version = "0.1.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "arrayvec 0.4.12",
  "bigint",
@@ -2157,7 +2157,7 @@ dependencies = [
 [[package]]
 name = "libp2p-dns"
 version = "0.13.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "futures",
  "libp2p-core",
@@ -2168,7 +2168,7 @@ dependencies = [
 [[package]]
 name = "libp2p-floodsub"
 version = "0.13.1"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "bs58 0.3.0",
  "bytes",
@@ -2186,7 +2186,7 @@ dependencies = [
 [[package]]
 name = "libp2p-gossipsub"
 version = "0.1.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "base64 0.10.1",
  "bs58 0.2.5",
@@ -2211,7 +2211,7 @@ dependencies = [
 [[package]]
 name = "libp2p-identify"
 version = "0.13.2"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "bytes",
  "futures",
@@ -2230,7 +2230,7 @@ dependencies = [
 [[package]]
 name = "libp2p-kad"
 version = "0.13.2"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "arrayvec 0.5.1",
  "bytes",
@@ -2257,7 +2257,7 @@ dependencies = [
 [[package]]
 name = "libp2p-mdns"
 version = "0.13.1"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "data-encoding",
  "dns-parser",
@@ -2279,7 +2279,7 @@ dependencies = [
 [[package]]
 name = "libp2p-mplex"
 version = "0.13.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "bytes",
  "fnv",
@@ -2295,7 +2295,7 @@ dependencies = [
 [[package]]
 name = "libp2p-noise"
 version = "0.11.1"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "bytes",
  "curve25519-dalek 1.2.3",
@@ -2315,7 +2315,7 @@ dependencies = [
 [[package]]
 name = "libp2p-ping"
 version = "0.13.1"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "bytes",
  "futures",
@@ -2332,7 +2332,7 @@ dependencies = [
 [[package]]
 name = "libp2p-plaintext"
 version = "0.13.1"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "bytes",
  "futures",
@@ -2347,7 +2347,7 @@ dependencies = [
 [[package]]
 name = "libp2p-secio"
 version = "0.13.1"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "aes-ctr",
  "bytes",
@@ -2376,7 +2376,7 @@ dependencies = [
 [[package]]
 name = "libp2p-swarm"
 version = "0.3.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "futures",
  "libp2p-core",
@@ -2389,7 +2389,7 @@ dependencies = [
 [[package]]
 name = "libp2p-tcp"
 version = "0.13.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "bytes",
  "futures",
@@ -2405,7 +2405,7 @@ dependencies = [
 [[package]]
 name = "libp2p-uds"
 version = "0.13.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "futures",
  "libp2p-core",
@@ -2416,7 +2416,7 @@ dependencies = [
 [[package]]
 name = "libp2p-wasm-ext"
 version = "0.6.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "futures",
  "js-sys",
@@ -2430,7 +2430,7 @@ dependencies = [
 [[package]]
 name = "libp2p-websocket"
 version = "0.13.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "bytes",
  "futures",
@@ -2448,7 +2448,7 @@ dependencies = [
 [[package]]
 name = "libp2p-yamux"
 version = "0.13.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "futures",
  "libp2p-core",
@@ -2747,7 +2747,7 @@ dependencies = [
 [[package]]
 name = "multistream-select"
 version = "0.6.1"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "bytes",
  "futures",
@@ -2980,7 +2980,7 @@ dependencies = [
 [[package]]
 name = "parity-multiaddr"
 version = "0.6.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "arrayref",
  "bs58 0.3.0",
@@ -2997,7 +2997,7 @@ dependencies = [
 [[package]]
 name = "parity-multihash"
 version = "0.2.0"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "blake2",
  "bytes",
@@ -3768,7 +3768,7 @@ dependencies = [
 [[package]]
 name = "rw-stream-sink"
 version = "0.1.2"
-source = "git+https://github.com/SigP/rust-libp2p?rev=44d7a9c9cd7be74109817bcabe74b991d5bd0fee#44d7a9c9cd7be74109817bcabe74b991d5bd0fee"
+source = "git+https://github.com/SigP/rust-libp2p?rev=4e3003d5283040fee10da1299252dd060a838d97#4e3003d5283040fee10da1299252dd060a838d97"
 dependencies = [
  "bytes",
  "futures",
diff --git a/beacon_node/eth2-libp2p/Cargo.toml b/beacon_node/eth2-libp2p/Cargo.toml
index f2428eeec..5cbf7dffb 100644
--- a/beacon_node/eth2-libp2p/Cargo.toml
+++ b/beacon_node/eth2-libp2p/Cargo.toml
@@ -8,7 +8,7 @@ edition = "2018"
 hex = "0.3"
 # rust-libp2p is presently being sourced from a Sigma Prime fork of the
 # `libp2p/rust-libp2p` repository.
-libp2p =  { git = "https://github.com/SigP/rust-libp2p", rev = "44d7a9c9cd7be74109817bcabe74b991d5bd0fee" }
+libp2p =  { git = "https://github.com/SigP/rust-libp2p", rev = "4e3003d5283040fee10da1299252dd060a838d97" }
 types = { path =  "../../eth2/types" }
 eth2_ssz_types = { path =  "../../eth2/utils/ssz_types" }
 serde = "1.0.102"
@@ -17,7 +17,6 @@ eth2_ssz = "0.1.2"
 eth2_ssz_derive = "0.1.0"
 slog = { version = "2.5.2", features = ["max_level_trace"] }
 version = { path = "../version" }
-# beacon_chain = { path = "../beacon_chain" }
 tokio = "0.1.22"
 futures = "0.1.29"
 error-chain = "0.12.1"
diff --git a/beacon_node/eth2-libp2p/src/behaviour.rs b/beacon_node/eth2-libp2p/src/behaviour.rs
index a5a5b575b..20a33e4e7 100644
--- a/beacon_node/eth2-libp2p/src/behaviour.rs
+++ b/beacon_node/eth2-libp2p/src/behaviour.rs
@@ -101,17 +101,12 @@ impl<TSubstream: AsyncRead + AsyncWrite, TSpec: EthSpec> Behaviour<TSubstream, T
 
     /// Subscribes to a gossipsub topic.
     pub fn subscribe(&mut self, topic: GossipTopic) -> bool {
-        if !self
-            .network_globals
+        // update the network globals
+        self.network_globals
             .gossipsub_subscriptions
-            .read()
-            .contains(&topic)
-        {
-            self.network_globals
-                .gossipsub_subscriptions
-                .write()
-                .push(topic.clone());
-        }
+            .write()
+            .insert(topic.clone());
+        // subscribe to the topic
         self.gossipsub.subscribe(topic.into())
     }
 
@@ -123,18 +118,12 @@ impl<TSubstream: AsyncRead + AsyncWrite, TSpec: EthSpec> Behaviour<TSubstream, T
 
     /// Unsubscribe from a gossipsub topic.
     pub fn unsubscribe(&mut self, topic: GossipTopic) -> bool {
-        let pos = self
-            .network_globals
+        // update the network globals
+        self.network_globals
             .gossipsub_subscriptions
-            .read()
-            .iter()
-            .position(|s| s == &topic);
-        if let Some(pos) = pos {
-            self.network_globals
-                .gossipsub_subscriptions
-                .write()
-                .swap_remove(pos);
-        }
+            .write()
+            .remove(&topic);
+        // unsubscribe from the topic
         self.gossipsub.unsubscribe(topic.into())
     }
 
diff --git a/beacon_node/eth2-libp2p/src/discovery/mod.rs b/beacon_node/eth2-libp2p/src/discovery/mod.rs
index 1ccc95767..466a3b7e0 100644
--- a/beacon_node/eth2-libp2p/src/discovery/mod.rs
+++ b/beacon_node/eth2-libp2p/src/discovery/mod.rs
@@ -12,7 +12,7 @@ use libp2p::discv5::enr::NodeId;
 use libp2p::discv5::{Discv5, Discv5Event};
 use libp2p::multiaddr::Protocol;
 use libp2p::swarm::{NetworkBehaviour, NetworkBehaviourAction, PollParameters, ProtocolsHandler};
-use slog::{debug, info, warn};
+use slog::{crit, debug, info, trace, warn};
 use ssz::{Decode, Encode};
 use ssz_types::BitVector;
 use std::collections::HashSet;
@@ -263,24 +263,88 @@ impl<TSubstream, TSpec: EthSpec> Discovery<TSubstream, TSpec> {
             });
 
         if peers_on_subnet < TARGET_SUBNET_PEERS {
+            let target_peers = TARGET_SUBNET_PEERS - peers_on_subnet;
             debug!(self.log, "Searching for peers for subnet";
                 "subnet_id" => *subnet_id,
                 "connected_peers_on_subnet" => peers_on_subnet,
-                "target_subnet_peers" => TARGET_SUBNET_PEERS
+                "target_subnet_peers" => TARGET_SUBNET_PEERS,
+                "target_peers" => target_peers
             );
-            // TODO: Update to predicate search
-            self.find_peers();
+
+            let log_clone = self.log.clone();
+
+            let subnet_predicate = move |enr: &Enr| {
+                if let Some(bitfield_bytes) = enr.get(BITFIELD_ENR_KEY) {
+                    let bitfield = match BitVector::<TSpec::SubnetBitfieldLength>::from_ssz_bytes(
+                        bitfield_bytes,
+                    ) {
+                        Ok(v) => v,
+                        Err(e) => {
+                            warn!(log_clone, "Could not decode ENR bitfield for peer"; "peer_id" => format!("{}", enr.peer_id()), "error" => format!("{:?}", e));
+                            return false;
+                        }
+                    };
+
+                    return bitfield.get(*subnet_id as usize).unwrap_or_else(|_| {
+                        debug!(log_clone, "Peer found but not on desired subnet"; "peer_id" => format!("{}", enr.peer_id()));
+                        false
+                    });
+                }
+                false
+            };
+
+            // start the query
+            self.start_query(subnet_predicate, target_peers as usize);
         }
+        debug!(self.log, "Discovery ignored";
+            "reason" => "Already connected to desired peers",
+            "connected_peers_on_subnet" => peers_on_subnet,
+            "target_subnet_peers" => TARGET_SUBNET_PEERS,
+        );
     }
 
     /* Internal Functions */
 
-    /// Search for new peers using the underlying discovery mechanism.
+    /// Run a standard query to search for more peers.
+    ///
+    /// This searches for the standard kademlia bucket size (16) peers.
     fn find_peers(&mut self) {
+        debug!(self.log, "Searching for peers");
+        self.start_query(|_| true, 16);
+    }
+
+    /// Search for a specified number of new peers using the underlying discovery mechanism.
+    ///
+    /// This can optionally search for peers for a given predicate. Regardless of the predicate
+    /// given, this will only search for peers on the same enr_fork_id as specified in the local
+    /// ENR.
+    fn start_query<F>(&mut self, enr_predicate: F, num_nodes: usize)
+    where
+        F: Fn(&Enr) -> bool + Send + 'static + Clone,
+    {
         // pick a random NodeId
         let random_node = NodeId::random();
-        debug!(self.log, "Searching for peers");
-        self.discovery.find_node(random_node);
+
+        let enr_fork_id = self.enr_fork_id().to_vec();
+        // predicate for finding nodes with a matching fork
+        let eth2_fork_predicate = move |enr: &Enr| enr.get(ETH2_ENR_KEY) == Some(&enr_fork_id);
+        let predicate = move |enr: &Enr| eth2_fork_predicate(enr) && enr_predicate(enr);
+
+        // general predicate
+        self.discovery
+            .find_enr_predicate(random_node, predicate, num_nodes);
+    }
+
+    /// Returns our current `eth2` field as SSZ bytes, associated with the local ENR. We only search for peers
+    /// that have this field.
+    fn enr_fork_id(&self) -> Vec<u8> {
+        self.local_enr()
+            .get(ETH2_ENR_KEY)
+            .map(|bytes| bytes.clone())
+            .unwrap_or_else(|| {
+                crit!(self.log, "Local ENR has no eth2 field");
+                Vec::new()
+            })
     }
 }
 
@@ -403,9 +467,16 @@ where
             match self.discovery.poll(params) {
                 Async::Ready(NetworkBehaviourAction::GenerateEvent(event)) => {
                     match event {
-                        Discv5Event::Discovered(_enr) => {
-                            // not concerned about FINDNODE results, rather the result of an entire
-                            // query.
+                        Discv5Event::Discovered(enr) => {
+                            // peers that get discovered during a query but are not contactable or
+                            // don't match a predicate can end up here. For debugging purposes we
+                            // log these to see if we are unnecessarily dropping discovered peers
+                            if enr.get(ETH2_ENR_KEY) == Some(&self.enr_fork_id().to_vec()) {
+                                trace!(self.log, "Peer found in process of query"; "peer_id" => format!("{}", enr.peer_id()), "tcp_socket" => enr.tcp_socket());
+                            } else {
+                                // this is temporary warning for debugging the DHT
+                                warn!(self.log, "Found peer during discovery not on correct fork"; "peer_id" => format!("{}", enr.peer_id()), "tcp_socket" => enr.tcp_socket());
+                            }
                         }
                         Discv5Event::SocketUpdated(socket) => {
                             info!(self.log, "Address updated"; "ip" => format!("{}",socket.ip()), "udp_port" => format!("{}", socket.port()));
diff --git a/beacon_node/eth2-libp2p/src/service.rs b/beacon_node/eth2-libp2p/src/service.rs
index b056eac05..3aefcce95 100644
--- a/beacon_node/eth2-libp2p/src/service.rs
+++ b/beacon_node/eth2-libp2p/src/service.rs
@@ -153,7 +153,7 @@ impl<TSpec: EthSpec> Service<TSpec> {
                 network_globals
                     .gossipsub_subscriptions
                     .write()
-                    .push(topic.clone());
+                    .insert(topic.clone());
             } else {
                 warn!(log, "Could not subscribe to topic"; "topic" => format!("{}",topic_string));
             }
diff --git a/beacon_node/eth2-libp2p/src/types/globals.rs b/beacon_node/eth2-libp2p/src/types/globals.rs
index 6fa6349fe..93574f9d8 100644
--- a/beacon_node/eth2-libp2p/src/types/globals.rs
+++ b/beacon_node/eth2-libp2p/src/types/globals.rs
@@ -1,7 +1,7 @@
 //! A collection of variables that are accessible outside of the network thread itself.
 use crate::{Enr, GossipTopic, Multiaddr, PeerId, PeerInfo};
 use parking_lot::RwLock;
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 use std::sync::atomic::{AtomicU16, Ordering};
 use types::EthSpec;
 
@@ -19,7 +19,7 @@ pub struct NetworkGlobals<TSpec: EthSpec> {
     /// The collection of currently connected peers.
     pub connected_peer_set: RwLock<HashMap<PeerId, PeerInfo<TSpec>>>,
     /// The current gossipsub topic subscriptions.
-    pub gossipsub_subscriptions: RwLock<Vec<GossipTopic>>,
+    pub gossipsub_subscriptions: RwLock<HashSet<GossipTopic>>,
 }
 
 impl<TSpec: EthSpec> NetworkGlobals<TSpec> {
@@ -31,7 +31,7 @@ impl<TSpec: EthSpec> NetworkGlobals<TSpec> {
             listen_port_tcp: AtomicU16::new(tcp_port),
             listen_port_udp: AtomicU16::new(udp_port),
             connected_peer_set: RwLock::new(HashMap::new()),
-            gossipsub_subscriptions: RwLock::new(Vec::new()),
+            gossipsub_subscriptions: RwLock::new(HashSet::new()),
         }
     }
 
diff --git a/beacon_node/eth2-libp2p/src/types/topics.rs b/beacon_node/eth2-libp2p/src/types/topics.rs
index 3745746a8..5ea0b1e76 100644
--- a/beacon_node/eth2-libp2p/src/types/topics.rs
+++ b/beacon_node/eth2-libp2p/src/types/topics.rs
@@ -19,7 +19,7 @@ pub const ATTESTER_SLASHING_TOPIC: &str = "attester_slashing";
 
 /// A gossipsub topic which encapsulates the type of messages that should be sent and received over
 /// the pubsub protocol and the way the messages should be encoded.
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, Hash)]
 pub struct GossipTopic {
     /// The encoding of the topic.
     encoding: GossipEncoding,
@@ -28,7 +28,7 @@ pub struct GossipTopic {
 }
 
 /// Enum that brings these topics into the rust type system.
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, Hash)]
 pub enum GossipKind {
     /// Topic for publishing beacon blocks.
     BeaconBlock,
@@ -45,7 +45,7 @@ pub enum GossipKind {
 }
 
 /// The known encoding types for gossipsub messages.
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, Hash)]
 pub enum GossipEncoding {
     /// Messages are encoded with SSZ.
     SSZ,