diff --git a/python/PyQt6/core/auto_generated/processing/qgsprocessingregistry.sip.in b/python/PyQt6/core/auto_generated/processing/qgsprocessingregistry.sip.in
index 2a1b6fea7d3..a4341672b30 100644
--- a/python/PyQt6/core/auto_generated/processing/qgsprocessingregistry.sip.in
+++ b/python/PyQt6/core/auto_generated/processing/qgsprocessingregistry.sip.in
@@ -87,7 +87,7 @@ Returns ``False`` if the provider could not be removed (eg provider does not exi
 .. seealso:: :py:func:`addProvider`
 %End
 
-    QgsProcessingProvider *providerById( const QString &id ) /HoldGIL/;
+    QgsProcessingProvider *providerById( const QString &id ) const /HoldGIL/;
 %Docstring
 Returns a matching provider by provider ID.
 %End
diff --git a/python/core/auto_generated/processing/qgsprocessingregistry.sip.in b/python/core/auto_generated/processing/qgsprocessingregistry.sip.in
index 2e100885d9e..65d37a5e796 100644
--- a/python/core/auto_generated/processing/qgsprocessingregistry.sip.in
+++ b/python/core/auto_generated/processing/qgsprocessingregistry.sip.in
@@ -87,7 +87,7 @@ Returns ``False`` if the provider could not be removed (eg provider does not exi
 .. seealso:: :py:func:`addProvider`
 %End
 
-    QgsProcessingProvider *providerById( const QString &id ) /HoldGIL/;
+    QgsProcessingProvider *providerById( const QString &id ) const /HoldGIL/;
 %Docstring
 Returns a matching provider by provider ID.
 %End
diff --git a/python/plugins/grassprovider/Grass7AlgorithmProvider.py b/python/plugins/grassprovider/Grass7AlgorithmProvider.py
index 5b6687442b9..a18511aa7fe 100644
--- a/python/plugins/grassprovider/Grass7AlgorithmProvider.py
+++ b/python/plugins/grassprovider/Grass7AlgorithmProvider.py
@@ -139,7 +139,7 @@ class Grass7AlgorithmProvider(QgsProcessingProvider):
         return 'GRASS GIS ({})'.format(version) if version is not None else "GRASS GIS"
 
     def id(self):
-        return 'grass7'
+        return 'grass'
 
     def helpId(self):
         return 'grass7'
diff --git a/src/core/processing/qgsprocessingregistry.cpp b/src/core/processing/qgsprocessingregistry.cpp
index 9e5e725801a..1a5495b9afc 100644
--- a/src/core/processing/qgsprocessingregistry.cpp
+++ b/src/core/processing/qgsprocessingregistry.cpp
@@ -103,7 +103,7 @@ bool QgsProcessingRegistry::addProvider( QgsProcessingProvider *provider )
   if ( !provider )
     return false;
 
-  if ( mProviders.contains( provider->id() ) )
+  if ( providerById( provider->id() ) )
   {
     QgsLogger::warning( QStringLiteral( "Duplicate provider %1 registered" ).arg( provider->id() ) );
     delete provider;
@@ -156,9 +156,17 @@ bool QgsProcessingRegistry::removeProvider( const QString &providerId )
   return removeProvider( p );
 }
 
-QgsProcessingProvider *QgsProcessingRegistry::providerById( const QString &id )
+QgsProcessingProvider *QgsProcessingRegistry::providerById( const QString &id ) const
 {
-  return mProviders.value( id, nullptr );
+  auto it = mProviders.constFind( id );
+  if ( it != mProviders.constEnd() )
+    return it.value();
+
+  // transparently map old references to "grass7" provider to "grass" provider
+  if ( id.compare( QLatin1String( "grass7" ), Qt::CaseInsensitive ) == 0 )
+    return providerById( QStringLiteral( "grass" ) );
+
+  return nullptr;
 }
 
 QList< const QgsProcessingAlgorithm * > QgsProcessingRegistry::algorithms() const
@@ -201,7 +209,7 @@ const QgsProcessingAlgorithm *QgsProcessingRegistry::algorithmById( const QStrin
   const QRegularExpressionMatch match = reSplitProviderId.match( id );
   if ( match.hasMatch() )
   {
-    if ( QgsProcessingProvider *provider = mProviders.value( match.captured( 1 ) ) )
+    if ( QgsProcessingProvider *provider = providerById( match.captured( 1 ) ) )
     {
       if ( const QgsProcessingAlgorithm *algorithm = provider->algorithm( match.captured( 2 ) ) )
         return algorithm;
diff --git a/src/core/processing/qgsprocessingregistry.h b/src/core/processing/qgsprocessingregistry.h
index 3ef54837652..478ed58f206 100644
--- a/src/core/processing/qgsprocessingregistry.h
+++ b/src/core/processing/qgsprocessingregistry.h
@@ -105,7 +105,7 @@ class CORE_EXPORT QgsProcessingRegistry : public QObject
     /**
      * Returns a matching provider by provider ID.
      */
-    QgsProcessingProvider *providerById( const QString &id ) SIP_HOLDGIL;
+    QgsProcessingProvider *providerById( const QString &id ) const SIP_HOLDGIL;
 
     /**
      * Returns a list of all available algorithms from registered providers.