diff --git a/python/core/auto_generated/processing/models/qgsprocessingmodelalgorithm.sip.in b/python/core/auto_generated/processing/models/qgsprocessingmodelalgorithm.sip.in
index d1b13ec931b..a0f2edc59d2 100644
--- a/python/core/auto_generated/processing/models/qgsprocessingmodelalgorithm.sip.in
+++ b/python/core/auto_generated/processing/models/qgsprocessingmodelalgorithm.sip.in
@@ -21,6 +21,9 @@ Model based algorithm with processing.
 %TypeHeaderCode
 #include "qgsprocessingmodelalgorithm.h"
 %End
+  public:
+    static const QMetaObject staticMetaObject;
+
   public:
 
     QgsProcessingModelAlgorithm( const QString &name = QString(), const QString &group = QString(), const QString &groupId = QString() );
@@ -575,6 +578,7 @@ run through the designer.
 .. versionadded:: 3.14
 %End
 
+
   protected:
 
     virtual QgsProcessingAlgorithm *createInstance() const /Factory/;
diff --git a/src/core/processing/models/qgsprocessingmodelalgorithm.cpp b/src/core/processing/models/qgsprocessingmodelalgorithm.cpp
index 2511892eba2..1dee5eb6046 100644
--- a/src/core/processing/models/qgsprocessingmodelalgorithm.cpp
+++ b/src/core/processing/models/qgsprocessingmodelalgorithm.cpp
@@ -1344,6 +1344,7 @@ QVariant QgsProcessingModelAlgorithm::toVariant() const
   map.insert( QStringLiteral( "model_name" ), mModelName );
   map.insert( QStringLiteral( "model_group" ), mModelGroup );
   map.insert( QStringLiteral( "help" ), mHelpContent );
+  map.insert( QStringLiteral( "internal_version" ), qgsEnumValueToKey( mInternalVersion ) );
 
   QVariantMap childMap;
   QMap< QString, QgsProcessingModelChildAlgorithm >::const_iterator childIt = mChildAlgorithms.constBegin();
@@ -1393,6 +1394,8 @@ bool QgsProcessingModelAlgorithm::loadVariant( const QVariant &model )
   mModelGroupId = map.value( QStringLiteral( "model_group" ) ).toString();
   mHelpContent = map.value( QStringLiteral( "help" ) ).toMap();
 
+  mInternalVersion = qgsEnumKeyToValue( map.value( QStringLiteral( "internal_version" ) ).toString(), InternalVersion::Version1 );
+
   mVariables = map.value( QStringLiteral( "modelVariables" ) ).toMap();
   mDesignerParameterValues = map.value( QStringLiteral( "designerParameterValues" ) ).toMap();
 
diff --git a/src/core/processing/models/qgsprocessingmodelalgorithm.h b/src/core/processing/models/qgsprocessingmodelalgorithm.h
index dfc7aca00f7..fc1ea96f8be 100644
--- a/src/core/processing/models/qgsprocessingmodelalgorithm.h
+++ b/src/core/processing/models/qgsprocessingmodelalgorithm.h
@@ -37,6 +37,8 @@
  */
 class CORE_EXPORT QgsProcessingModelAlgorithm : public QgsProcessingAlgorithm
 {
+    Q_GADGET
+
   public:
 
     /**
@@ -523,6 +525,18 @@ class CORE_EXPORT QgsProcessingModelAlgorithm : public QgsProcessingAlgorithm
      */
     void setDesignerParameterValues( const QVariantMap &values ) { mDesignerParameterValues = values; }
 
+#ifndef SIP_RUN
+
+    //! Internal model versions
+    enum class InternalVersion
+    {
+      Version1, //!< Created in < 3.26
+      Version2, //!< Created in >= 3.26
+    };
+    Q_ENUM( InternalVersion )
+
+#endif
+
   protected:
 
     QgsProcessingAlgorithm *createInstance() const override SIP_FACTORY;
@@ -531,6 +545,8 @@ class CORE_EXPORT QgsProcessingModelAlgorithm : public QgsProcessingAlgorithm
 
   private:
 
+    InternalVersion mInternalVersion = InternalVersion::Version2;
+
     QString mModelName;
     QString mModelGroup;
     QString mModelGroupId;
diff --git a/tests/src/analysis/testqgsprocessingmodelalgorithm.cpp b/tests/src/analysis/testqgsprocessingmodelalgorithm.cpp
index 6878a1cab18..e4a44961b72 100644
--- a/tests/src/analysis/testqgsprocessingmodelalgorithm.cpp
+++ b/tests/src/analysis/testqgsprocessingmodelalgorithm.cpp
@@ -105,6 +105,7 @@ class TestQgsProcessingModelAlgorithm: public QObject
     void modelSource();
     void modelNameMatchesFileName();
     void renameModelParameter();
+    void internalVersion();
 
   private:
 
@@ -2204,5 +2205,21 @@ void TestQgsProcessingModelAlgorithm::renameModelParameter()
   QCOMPARE( m.childAlgorithm( QStringLiteral( "cx1" ) ).parameterSources()[ QStringLiteral( "EXPRESSION" ) ].constFirst().expression(), QStringLiteral( "@apricot * 2 + @int2" ) );
 }
 
+void TestQgsProcessingModelAlgorithm::internalVersion()
+{
+  // test internal version handling
+  QgsProcessingModelAlgorithm model;
+
+  // load older model, should be version 1
+  QVERIFY( model.fromFile( TEST_DATA_DIR + QStringLiteral( "/test_model.model3" ) ) );
+  QCOMPARE( model.mInternalVersion, QgsProcessingModelAlgorithm::InternalVersion::Version1 );
+
+  // create new model and save/restore, should be version 2
+  QgsProcessingModelAlgorithm model2;
+  QgsProcessingModelAlgorithm model3;
+  QVERIFY( model3.loadVariant( model2.toVariant() ) );
+  QCOMPARE( model3.mInternalVersion, QgsProcessingModelAlgorithm::InternalVersion::Version2 );
+}
+
 QGSTEST_MAIN( TestQgsProcessingModelAlgorithm )
 #include "testqgsprocessingmodelalgorithm.moc"