diff --git a/tdutils/td/utils/port/IPAddress.h b/tdutils/td/utils/port/IPAddress.h
index ce654872..7d61b7a1 100644
--- a/tdutils/td/utils/port/IPAddress.h
+++ b/tdutils/td/utils/port/IPAddress.h
@@ -40,6 +40,8 @@ class IPAddress {
 
   uint32 get_ipv4() const;
   string get_ipv6() const;
+
+  // returns result in a static thread-local buffer, which may be overwritten by any subsequent method call
   Slice get_ip_str() const;
 
   static string ipv4_to_str(uint32 ipv4);