diff --git a/testmodule/providers/jsonrpc/rpc_mock.nim b/testmodule/providers/jsonrpc/rpc_mock.nim
index e747ada..78a3a25 100644
--- a/testmodule/providers/jsonrpc/rpc_mock.nim
+++ b/testmodule/providers/jsonrpc/rpc_mock.nim
@@ -6,7 +6,7 @@ import std/tables
 import pkg/stew/byteutils
 import pkg/json_rpc/rpcserver except `%`, `%*`
 import pkg/json_rpc/errors
-
+import std/random
 
 type MockRpcHttpServer* = ref object
   filters*: Table[string, bool]
@@ -14,7 +14,10 @@ type MockRpcHttpServer* = ref object
   srv: RpcHttpServer
 
 proc new*(_: type MockRpcHttpServer): MockRpcHttpServer =
-  MockRpcHttpServer(filters: initTable[string, bool](), newFilterCounter: 0, srv: newRpcHttpServer(["127.0.0.1:65080"]))
+  let port = rand(65000..<66000)
+  let srv = newRpcHttpServer(["127.0.0.1:" & port])
+  let filters = initTable[string, bool]()
+  MockRpcHttpServer(filters: filters, newFilterCounter: 0, srv: srv)
 
 proc invalidateFilter*(server: MockRpcHttpServer, id: string) =
   server.filters[id] = false
diff --git a/testmodule/providers/jsonrpc/testJsonRpcSubscriptions.nim b/testmodule/providers/jsonrpc/testJsonRpcSubscriptions.nim
index 48342ca..49159bc 100644
--- a/testmodule/providers/jsonrpc/testJsonRpcSubscriptions.nim
+++ b/testmodule/providers/jsonrpc/testJsonRpcSubscriptions.nim
@@ -128,18 +128,29 @@ suite "HTTP polling subscriptions - filter not found":
     await mockServer.stop()
 
   test "filter not found error recreates filter":
+    echo "1"
     let filter = EventFilter(address: Address.example, topics: @[array[32, byte].example])
+    echo "2"
     let emptyHandler = proc(log: Log) = discard
+    echo "3"
 
     check mockServer.newFilterCounter == 0
+    echo "4"
     let jsonId = await subscriptions.subscribeLogs(filter, emptyHandler)
+    echo "5"
     let id = string.fromJson(jsonId).tryGet
+    echo "6"
     check mockServer.newFilterCounter == 1
+    echo "7"
 
     await sleepAsync(50.millis)
+    echo "8"
     mockServer.invalidateFilter(id)
+    echo "9"
     await sleepAsync(50.millis)
+    echo "10"
     check mockServer.newFilterCounter == 2
+    echo "11"
 
   test "recreated filter can be still unsubscribed using the original id":
     let filter = EventFilter(address: Address.example, topics: @[array[32, byte].example])