diff --git a/release/models/interfaces/openconfig-interfaces.yang b/release/models/interfaces/openconfig-interfaces.yang
index 6d79517cdd..fbaaa1692b 100644
--- a/release/models/interfaces/openconfig-interfaces.yang
+++ b/release/models/interfaces/openconfig-interfaces.yang
@@ -9,9 +9,9 @@ module openconfig-interfaces {
 
   // import some basic types
   import ietf-interfaces { prefix ietf-if; }
-  import openconfig-yang-types { prefix oc-yang; }
   import openconfig-types { prefix oc-types; }
   import openconfig-extensions { prefix oc-ext; }
+  import openconfig-yang-types { prefix oc-yang; }
   import openconfig-transport-types { prefix oc-opt-types; }
 
   // meta
@@ -1292,7 +1292,7 @@ module openconfig-interfaces {
           description
             "Configurable items at the subinterface level";
           oc-ext:telemetry-on-change;
-
+          oc-ext:allow-config-mismatch;
           uses subinterfaces-config;
         }
 
@@ -1346,6 +1346,7 @@ module openconfig-interfaces {
             "Configurable items at the global, physical interface
             level";
           oc-ext:telemetry-on-change;
+          oc-ext:allow-config-mismatch;
 
           uses interface-phys-config;
         }
diff --git a/release/models/openconfig-extensions.yang b/release/models/openconfig-extensions.yang
index 4d912367d5..386306cdc2 100644
--- a/release/models/openconfig-extensions.yang
+++ b/release/models/openconfig-extensions.yang
@@ -18,7 +18,13 @@ module openconfig-extensions {
     "This module provides extensions to the YANG language to allow
     OpenConfig specific functionality and meta-data to be defined.";
 
-  oc-ext:openconfig-version "0.7.0";
+  oc-ext:openconfig-version "1.0.0";
+
+  revision "2026-02-04" {
+    description
+    "Add allow-config-mismatch extension.";
+    reference "1.0.0";
+  }
 
   revision "2025-01-02" {
     description
@@ -68,6 +74,15 @@ module openconfig-extensions {
     reference "0.1.0";
   }
 
+  extension allow-config-mismatch {
+    description
+      "This extension is applied to configuration leaves or containers that
+      may contain values which mismatch or are invalid for currently
+      installed hardware.  The target must accepted these invalid
+      values and should generate a warning message.  In this case
+      the related hardware component is expected to be in an operational
+      down or error state.";
+  }
 
   // extension statements
   extension openconfig-version {