diff --git a/eth_p2p/rlpx_protocols/shh_protocol.nim b/eth_p2p/rlpx_protocols/shh_protocol.nim
index 2910f49..d299697 100644
--- a/eth_p2p/rlpx_protocols/shh_protocol.nim
+++ b/eth_p2p/rlpx_protocols/shh_protocol.nim
@@ -112,6 +112,8 @@ type
     handler: Option[FilterMsgHandler]
     queue: seq[ReceivedMessage]
 
+  Filters* = Table[string, Filter]
+
   WhisperConfig* = object
     powRequirement*: float64
     bloom*: Bloom
@@ -558,7 +560,22 @@ proc newFilter*(src = none[PublicKey](), privateKey = none[PrivateKey](),
   Filter(src: src, privateKey: privateKey, symKey: symKey, topics: topics,
          powReq: powReq, allowP2P: allowP2P, bloom: toBloom(topics))
 
-proc notify(filters: var Table[string, Filter], msg: Message) =
+proc subscribeFilter*(filters: var Filters, filter: Filter,
+                      handler = none[FilterMsgHandler]()): string =
+  # NOTE: Should we allow a filter without a key? Encryption is mandatory in v6?
+  # Check if asymmetric _and_ symmetric key? Now asymmetric just has precedence.
+  let id = generateRandomID()
+  var filter = filter
+  if handler.isSome():
+   filter.handler = handler
+  else:
+   filter.queue = newSeqOfCap[ReceivedMessage](defaultFilterQueueCapacity)
+
+  filters.add(id, filter)
+  debug "Filter added", filter = id
+  return id
+
+proc notify*(filters: var Filters, msg: Message) =
  var decoded: Option[DecodedPayload]
  var keyHash: Hash
 
@@ -616,6 +633,19 @@ proc notify(filters: var Table[string, Filter], msg: Message) =
    else:
      filter.queue.insert(receivedMsg)
 
+proc getFilterMessages*(filters: var Filters, filterId: string): seq[ReceivedMessage] =
+  result = @[]
+  if filters.contains(filterId):
+    if filters[filterId].handler.isNone():
+      result = filters[filterId].queue
+      filters[filterId].queue =
+        newSeqOfCap[ReceivedMessage](defaultFilterQueueCapacity)
+
+proc toBloom*(filters: Filters): Bloom =
+  for filter in filters.values:
+    if filter.topics.len > 0:
+      result = result or filter.bloom
+
 type
   PeerState = ref object
     initialized*: bool # when successfully completed the handshake
@@ -628,7 +658,7 @@ type
 
   WhisperState = ref object
     queue*: Queue
-    filters*: Table[string, Filter]
+    filters*: Filters
     config*: WhisperConfig
 
 proc run(peer: Peer) {.async.}
@@ -868,29 +898,17 @@ proc postMessage*(node: EthereumNode, pubKey = none[PublicKey](),
 
 proc subscribeFilter*(node: EthereumNode, filter: Filter,
                       handler = none[FilterMsgHandler]()): string =
-  # NOTE: Should we allow a filter without a key? Encryption is mandatory in v6?
-  # Check if asymmetric _and_ symmetric key? Now asymmetric just has precedence.
-  let id = generateRandomID()
-  var filter = filter
-  if handler.isSome():
-    filter.handler = handler
-  else:
-    filter.queue = newSeqOfCap[ReceivedMessage](defaultFilterQueueCapacity)
-  node.protocolState(shh).filters.add(id, filter)
-  debug "Filter added", filter = id
-  return id
+  return node.protocolState(shh).filters.subscribeFilter(filter, handler)
 
 proc unsubscribeFilter*(node: EthereumNode, filterId: string): bool =
   var filter: Filter
   return node.protocolState(shh).filters.take(filterId, filter)
 
 proc getFilterMessages*(node: EthereumNode, filterId: string): seq[ReceivedMessage] =
-  result = @[]
-  if node.protocolState(shh).filters.contains(filterId):
-    if node.protocolState(shh).filters[filterId].handler.isNone():
-      result = node.protocolState(shh).filters[filterId].queue
-      node.protocolState(shh).filters[filterId].queue =
-        newSeqOfCap[ReceivedMessage](defaultFilterQueueCapacity)
+  return node.protocolState(shh).filters.getFilterMessages(filterId)
+
+proc filtersToBloom*(node: EthereumNode): Bloom =
+  return node.protocolState(shh).filters.toBloom()
 
 proc setPowRequirement*(node: EthereumNode, powReq: float64) {.async.} =
   # NOTE: do we need a tolerance of old PoW for some time?
@@ -906,11 +924,6 @@ proc setBloomFilter*(node: EthereumNode, bloom: Bloom) {.async.} =
     # asyncCheck peer.bloomFilterExchange(@bloom)
     await peer.bloomFilterExchange(@bloom)
 
-proc filtersToBloom*(node: EthereumNode): Bloom =
-  for filter in node.protocolState(shh).filters.values:
-    if filter.topics.len > 0:
-      result = result or filter.bloom
-
 proc setMaxMessageSize*(node: EthereumNode, size: uint32): bool =
   if size > defaultMaxMsgSize:
     error "size > maxMsgSize"
diff --git a/tests/tshh.nim b/tests/tshh.nim
index 05dd2c6..0d01957 100644
--- a/tests/tshh.nim
+++ b/tests/tshh.nim
@@ -8,7 +8,7 @@
 #            MIT license (LICENSE-MIT)
 
 import
-  sequtils, options, unittest, times,
+  sequtils, options, unittest, times, tables,
   nimcrypto/hash,
   eth_keys, rlp,
   eth_p2p/rlpx_protocols/shh_protocol as shh
@@ -274,3 +274,95 @@ suite "Whisper queue":
   test "check field order against expected rlp order":
     check rlp.encode(env0) ==
       rlp.encodeList(env0.expiry, env0.ttl, env0.topic, env0.data, env0.nonce)
+
+# To test filters we do not care if the msg is valid or allowed
+proc prepFilterTestMsg(pubKey = none[PublicKey](), symKey = none[SymKey](),
+                       src = none[PrivateKey](), topic: Topic): Message =
+    let payload = Payload(dst: pubKey, symKey: symKey, src: src,
+                          payload: @[byte 0, 1, 2])
+    let encoded = shh.encode(payload)
+    let env = Envelope(expiry: 1, ttl: 1, topic: topic, data: encoded.get(),
+                       nonce: 0)
+    result = initMessage(env)
+
+suite "Whisper filter":
+  test "should notify filter on message with symmetric encryption":
+    var symKey: SymKey
+    let topic = [byte 0, 0, 0, 0]
+    let msg = prepFilterTestMsg(symKey = some(symKey), topic = topic)
+
+    var filters = initTable[string, Filter]()
+    let filter = newFilter(symKey = some(symKey), topics = @[topic])
+    let filterId = filters.subscribeFilter(filter)
+
+    notify(filters, msg)
+
+    let messages = filters.getFilterMessages(filterId)
+    check messages.len == 1
+
+  test "should notify filter on message with asymmetric encryption":
+    let privKey = eth_keys.newPrivateKey()
+    let topic = [byte 0, 0, 0, 0]
+    let msg = prepFilterTestMsg(pubKey = some(privKey.getPublicKey()),
+                                topic = topic)
+
+    var filters = initTable[string, Filter]()
+    let filter = newFilter(privateKey = some(privKey), topics = @[topic])
+    let filterId = filters.subscribeFilter(filter)
+
+    notify(filters, msg)
+
+    let messages = filters.getFilterMessages(filterId)
+    check messages.len == 1
+
+  test "should notify filter on message with signature":
+    let privKey = eth_keys.newPrivateKey()
+    let topic = [byte 0, 0, 0, 0]
+    let msg = prepFilterTestMsg(src = some(privKey), topic = topic)
+
+    var filters = initTable[string, Filter]()
+    let filter = newFilter(src = some(privKey.getPublicKey()),
+                           topics = @[topic])
+    let filterId = filters.subscribeFilter(filter)
+
+    notify(filters, msg)
+
+    let messages = filters.getFilterMessages(filterId)
+    check messages.len == 1
+
+  test "test notify of filter against PoW requirement":
+    let topic = [byte 0, 0, 0, 0]
+    # this message has a PoW of 0.02962962962962963, number should be updated
+    # in case PoW algorithm changes
+    let msg = prepFilterTestMsg(topic = topic)
+
+    var filters = initTable[string, Filter]()
+    let
+      filterId1 = filters.subscribeFilter(
+                    newFilter(topics = @[topic], powReq = 0.02962962962962963))
+      filterId2 = filters.subscribeFilter(
+                    newFilter(topics = @[topic], powReq = 0.02962962962962964))
+
+    notify(filters, msg)
+
+    check:
+      filters.getFilterMessages(filterId1).len == 1
+      filters.getFilterMessages(filterId2).len == 0
+
+  test "test notify of filter on message with certain topic":
+    let
+      topic1 = [byte 0xAB, 0x12, 0xCD, 0x34]
+      topic2 = [byte 0, 0, 0, 0]
+
+    let msg = prepFilterTestMsg(topic = topic1)
+
+    var filters = initTable[string, Filter]()
+    let
+      filterId1 = filters.subscribeFilter(newFilter(topics = @[topic1]))
+      filterId2 = filters.subscribeFilter(newFilter(topics = @[topic2]))
+
+    notify(filters, msg)
+
+    check:
+      filters.getFilterMessages(filterId1).len == 1
+      filters.getFilterMessages(filterId2).len == 0