diff --git a/core/src/rpc_subscriptions.rs b/core/src/rpc_subscriptions.rs
index 7072443d36..5420d229e9 100644
--- a/core/src/rpc_subscriptions.rs
+++ b/core/src/rpc_subscriptions.rs
@@ -1,6 +1,7 @@
 //! The `pubsub` module implements a threaded subscription service on client RPC request
 
 use crate::rpc_status::RpcSignatureStatus;
+use core::hash::Hash;
 use jsonrpc_core::futures::Future;
 use jsonrpc_pubsub::typed::Sink;
 use jsonrpc_pubsub::SubscriptionId;
@@ -14,6 +15,46 @@ use std::sync::RwLock;
 type RpcAccountSubscriptions = RwLock<HashMap<Pubkey, HashMap<SubscriptionId, Sink<Account>>>>;
 type RpcSignatureSubscriptions =
     RwLock<HashMap<Signature, HashMap<SubscriptionId, Sink<RpcSignatureStatus>>>>;
+
+fn add_subscription<K, S>(
+    subscriptions: &mut HashMap<K, HashMap<SubscriptionId, Sink<S>>>,
+    hashmap_key: &K,
+    sub_id: &SubscriptionId,
+    sink: &Sink<S>,
+) where
+    K: Eq + Hash + Clone + Copy,
+    S: Clone,
+{
+    if let Some(current_hashmap) = subscriptions.get_mut(hashmap_key) {
+        current_hashmap.insert(sub_id.clone(), sink.clone());
+        return;
+    }
+    let mut hashmap = HashMap::new();
+    hashmap.insert(sub_id.clone(), sink.clone());
+    subscriptions.insert(*hashmap_key, hashmap);
+}
+
+fn remove_subscription<K, S>(
+    subscriptions: &mut HashMap<K, HashMap<SubscriptionId, Sink<S>>>,
+    sub_id: &SubscriptionId,
+) -> bool
+where
+    K: Eq + Hash + Clone + Copy,
+    S: Clone,
+{
+    let mut found = false;
+    subscriptions.retain(|_, v| {
+        v.retain(|k, _| {
+            if *k == *sub_id {
+                found = true;
+            }
+            !found
+        });
+        !v.is_empty()
+    });
+    found
+}
+
 pub struct RpcSubscriptions {
     account_subscriptions: RpcAccountSubscriptions,
     signature_subscriptions: RpcSignatureSubscriptions,
@@ -62,28 +103,12 @@ impl RpcSubscriptions {
         sink: &Sink<Account>,
     ) {
         let mut subscriptions = self.account_subscriptions.write().unwrap();
-        if let Some(current_hashmap) = subscriptions.get_mut(pubkey) {
-            current_hashmap.insert(sub_id.clone(), sink.clone());
-            return;
-        }
-        let mut hashmap = HashMap::new();
-        hashmap.insert(sub_id.clone(), sink.clone());
-        subscriptions.insert(*pubkey, hashmap);
+        add_subscription(&mut subscriptions, pubkey, sub_id, sink);
     }
 
     pub fn remove_account_subscription(&self, id: &SubscriptionId) -> bool {
         let mut subscriptions = self.account_subscriptions.write().unwrap();
-        let mut found = false;
-        subscriptions.retain(|_, v| {
-            v.retain(|k, _| {
-                if *k == *id {
-                    found = true;
-                }
-                !found
-            });
-            !v.is_empty()
-        });
-        found
+        remove_subscription(&mut subscriptions, id)
     }
 
     pub fn add_signature_subscription(
@@ -93,28 +118,12 @@ impl RpcSubscriptions {
         sink: &Sink<RpcSignatureStatus>,
     ) {
         let mut subscriptions = self.signature_subscriptions.write().unwrap();
-        if let Some(current_hashmap) = subscriptions.get_mut(signature) {
-            current_hashmap.insert(sub_id.clone(), sink.clone());
-            return;
-        }
-        let mut hashmap = HashMap::new();
-        hashmap.insert(sub_id.clone(), sink.clone());
-        subscriptions.insert(*signature, hashmap);
+        add_subscription(&mut subscriptions, signature, sub_id, sink);
     }
 
     pub fn remove_signature_subscription(&self, id: &SubscriptionId) -> bool {
         let mut subscriptions = self.signature_subscriptions.write().unwrap();
-        let mut found = false;
-        subscriptions.retain(|_, v| {
-            v.retain(|k, _| {
-                if *k == *id {
-                    found = true;
-                }
-                !found
-            });
-            !v.is_empty()
-        });
-        found
+        remove_subscription(&mut subscriptions, id)
     }
 
     /// Notify subscribers of changes to any accounts or new signatures since