diff --git a/include/openthread/instance.h b/include/openthread/instance.h
index be53ca2c4..cf152ae60 100644
--- a/include/openthread/instance.h
+++ b/include/openthread/instance.h
@@ -53,7 +53,7 @@ extern "C" {
  * @note This number versions both OpenThread platform and user APIs.
  *
  */
-#define OPENTHREAD_API_VERSION (19)
+#define OPENTHREAD_API_VERSION (20)
 
 /**
  * @addtogroup api-instance
diff --git a/include/openthread/ip6.h b/include/openthread/ip6.h
index e1f99c28c..ef169607a 100644
--- a/include/openthread/ip6.h
+++ b/include/openthread/ip6.h
@@ -205,7 +205,6 @@ typedef struct otSockAddr
 {
     otIp6Address mAddress; ///< An IPv6 address.
     uint16_t     mPort;    ///< A transport-layer port.
-    int8_t       mScopeId; ///< An IPv6 scope identifier.
 } otSockAddr;
 
 /**