diff --git a/DXFeedFramework/Native/Graal/Isolate.swift b/DXFeedFramework/Native/Graal/Isolate.swift
index 2ca2d673a..fc23f9589 100644
--- a/DXFeedFramework/Native/Graal/Isolate.swift
+++ b/DXFeedFramework/Native/Graal/Isolate.swift
@@ -27,6 +27,13 @@ class Isolate {
     }
 
     init() {
-        try? ErrorCheck.graalCall(graal_create_isolate(self.params, self.isolate, thread))
+        print("DXFeedFramework.Isolate:init \(Thread.isMainThread) \(Thread.current) \(Thread.current.threadName)")
+        if Thread.isMainThread {
+            try? ErrorCheck.graalCall(graal_create_isolate(self.params, self.isolate, self.thread))
+        } else {
+            DispatchQueue.main.sync {
+                try? ErrorCheck.graalCall(graal_create_isolate(self.params, self.isolate, self.thread))
+            }
+        }
     }
 }
diff --git a/DXFeedFramework/Native/Graal/IsolateThread.swift b/DXFeedFramework/Native/Graal/IsolateThread.swift
index 3b0fff068..b02082bcc 100644
--- a/DXFeedFramework/Native/Graal/IsolateThread.swift
+++ b/DXFeedFramework/Native/Graal/IsolateThread.swift
@@ -33,7 +33,7 @@ Required thread:  \(threadName). Current thread: \(Thread.current.threadName)
 
 }
 
-private extension Thread {
+internal extension Thread {
     var threadName: String {
         if let currentOperationQueue = OperationQueue.current?.name {
             return "OperationQueue: \(currentOperationQueue)"