diff --git a/src/main/java/com/microsoft/sqlserver/jdbc/AuthenticationJNI.java b/src/main/java/com/microsoft/sqlserver/jdbc/AuthenticationJNI.java
index f4dede521..fc8210f04 100644
--- a/src/main/java/com/microsoft/sqlserver/jdbc/AuthenticationJNI.java
+++ b/src/main/java/com/microsoft/sqlserver/jdbc/AuthenticationJNI.java
@@ -153,7 +153,7 @@ private static native int SNISecGenClientContext(byte[] psec, int[] secptrsize,
 
     private static native int GetDNSName(String address, String[] DNSName, java.util.logging.Logger log);
 
-    private static native FedAuthDllInfo ADALGetAccessTokenForWindowsIntegrated(String stsURL,
+    private static synchronized native FedAuthDllInfo ADALGetAccessTokenForWindowsIntegrated(String stsURL,
             String servicePrincipalName, String clientConnectionId, String clientId, long expirationFileTime,
             java.util.logging.Logger log);