diff --git a/ogrgrass.h b/ogrgrass.h
index 2687363..967d77e 100644
--- a/ogrgrass.h
+++ b/ogrgrass.h
@@ -127,8 +127,8 @@ class OGRGRASSDataSource final: public OGRDataSource
                         OGRGRASSDataSource();
                         virtual ~OGRGRASSDataSource();
 
-    int                 Open( const char *, int bUpdate, int bTestOpen,
-                              int bSingleNewFile = FALSE );
+    bool                Open( const char *, bool bUpdate, bool bTestOpen,
+                              bool bSingleNewFile = false );
 
     const char          *GetName() override { return pszName; }
     int                 GetLayerCount() override { return nLayers; }
@@ -147,23 +147,9 @@ class OGRGRASSDataSource final: public OGRDataSource
     struct Map_info     map;
     int                 nLayers;
 
-    int                 bOpened;
+    bool                bOpened;
 
     static bool SplitPath ( char *, char **, char **, char **, char ** );
 };
 
-/************************************************************************/
-/*                            OGRGRASSDriver                            */
-/************************************************************************/
-class OGRGRASSDriver final: public OGRSFDriver
-{
-  public:
-                        virtual ~OGRGRASSDriver();
-
-    const char          *GetName() override;
-    OGRDataSource       *Open( const char *, int ) override;
-
-    int                 TestCapability( const char * ) override;
-};
-
 #endif /* ndef OGRGRASS_H_INCLUDED */
diff --git a/ogrgrassdatasource.cpp b/ogrgrassdatasource.cpp
index e7b480c..cd378f0 100644
--- a/ogrgrassdatasource.cpp
+++ b/ogrgrassdatasource.cpp
@@ -87,8 +87,8 @@ OGRGRASSDataSource::~OGRGRASSDataSource()
 
 typedef int (*GrassErrorHandler)(const char *, int);
 
-int OGRGRASSDataSource::Open( const char * pszNewName, int /*bUpdate*/,
-                              int bTestOpen, int /*bSingleNewFileIn*/ )
+bool OGRGRASSDataSource::Open( const char * pszNewName, bool /*bUpdate*/,
+                               bool bTestOpen, bool /*bSingleNewFileIn*/ )
 {
     VSIStatBuf  stat;
 
@@ -99,14 +99,14 @@ int OGRGRASSDataSource::Open( const char * pszNewName, int /*bUpdate*/,
 /* -------------------------------------------------------------------- */
 /*      Do the given path contains 'vector' and 'head'?                 */
 /* -------------------------------------------------------------------- */
-    if ( strstr(pszName,"vector") == NULL || strstr(pszName,"head") == NULL )
+    if ( strstr(pszName,"vector") == nullptr || strstr(pszName,"head") == nullptr )
     {
         if( !bTestOpen )
         {
             CPLError( CE_Failure, CPLE_AppDefined,
                  "%s is not GRASS vector, access failed.\n", pszName );
         }
-        return FALSE;
+        return false;
     }
 
 /* -------------------------------------------------------------------- */
@@ -120,7 +120,7 @@ int OGRGRASSDataSource::Open( const char * pszNewName, int /*bUpdate*/,
                  "%s is not GRASS vector, access failed.\n", pszName );
         }
 
-        return FALSE;
+        return false;
     }
 
 /* -------------------------------------------------------------------- */
@@ -135,7 +135,7 @@ int OGRGRASSDataSource::Open( const char * pszNewName, int /*bUpdate*/,
                       "%s is not GRASS datasource name, access failed.\n",
                       pszName );
         }
-        return FALSE;
+        return false;
     }
 
     CPLDebug ( "GRASS", "Gisdbase: %s", pszGisdbase );
@@ -149,7 +149,7 @@ int OGRGRASSDataSource::Open( const char * pszNewName, int /*bUpdate*/,
     // GISBASE is path to the directory where GRASS is installed,
     // it is necessary because there are database drivers.
     if ( !getenv( "GISBASE" ) ) {
-        static char* gisbaseEnv = NULL;
+        static char* gisbaseEnv = nullptr;
         const char *gisbase = GRASS_GISBASE;
         CPLError( CE_Warning, CPLE_AppDefined, "GRASS warning: GISBASE "
                 "environment variable was not set, using:\n%s", gisbase );
@@ -191,7 +191,7 @@ int OGRGRASSDataSource::Open( const char * pszNewName, int /*bUpdate*/,
     if ( level < 2 ) {
         CPLError( CE_Failure, CPLE_AppDefined,
                  "Cannot open GRASS vector %s on level 2.\n", pszName );
-        return FALSE;
+        return false;
     }
 
     CPLDebug ( "GRASS", "Num lines = %d", Vect_get_num_lines(&map) );
@@ -212,9 +212,9 @@ int OGRGRASSDataSource::Open( const char * pszNewName, int /*bUpdate*/,
         papoLayers[nLayers++] = poLayer;
     }
 
-    bOpened = TRUE;
+    bOpened = true;
 
-    return TRUE;
+    return true;
 }
 
 /************************************************************************/
diff --git a/ogrgrassdriver.cpp b/ogrgrassdriver.cpp
index 3849374..8f302b4 100644
--- a/ogrgrassdriver.cpp
+++ b/ogrgrassdriver.cpp
@@ -36,33 +36,19 @@ extern "C" {
 
 CPL_CVSID("$Id$")
 
-/************************************************************************/
-/*                          ~OGRGRASSDriver()                           */
-/************************************************************************/
-OGRGRASSDriver::~OGRGRASSDriver()
-{
-}
-
-/************************************************************************/
-/*                              GetName()                               */
-/************************************************************************/
-const char *OGRGRASSDriver::GetName()
-{
-    return "OGR_GRASS";
-}
-
 /************************************************************************/
 /*                                Open()                                */
 /************************************************************************/
-OGRDataSource *OGRGRASSDriver::Open( const char * pszFilename,
-                                     int bUpdate )
+static auto GRASSDatasetOpen(GDALOpenInfo *poOpenInfo) -> GDALDataset*
 {
-    OGRGRASSDataSource  *poDS = new OGRGRASSDataSource();
+    auto *poDS = new OGRGRASSDataSource();
+
+    bool bUpdate = poOpenInfo->eAccess == GA_Update;
 
-    if( !poDS->Open( pszFilename, bUpdate, TRUE ) )
+    if( !poDS->Open( poOpenInfo->pszFilename, bUpdate, true ))
     {
         delete poDS;
-        return NULL;
+        return nullptr;
     }
     else
     {
@@ -70,14 +56,6 @@ OGRDataSource *OGRGRASSDriver::Open( const char * pszFilename,
     }
 }
 
-/************************************************************************/
-/*                           TestCapability()                           */
-/************************************************************************/
-int OGRGRASSDriver::TestCapability( const char * /*pszCap*/ )
-{
-    return FALSE;
-}
-
 /************************************************************************/
 /*                          RegisterOGRGRASS()                          */
 /************************************************************************/
@@ -86,15 +64,17 @@ void RegisterOGRGRASS()
     if (! GDAL_CHECK_VERSION("OGR/GRASS driver"))
         return;
 
-    if( GDALGetDriverByName( "OGR_GRASS" ) != NULL )
+    if( GDALGetDriverByName( "OGR_GRASS" ) != nullptr )
         return;
 
-    OGRGRASSDriver *poDriver = new OGRGRASSDriver();
+    auto *poDriver = new GDALDriver();
 
-    poDriver->SetDescription( "GRASS" );
+    poDriver->SetDescription( "OGR_GRASS" );
     poDriver->SetMetadataItem( GDAL_DCAP_VECTOR, "YES" );
     poDriver->SetMetadataItem( GDAL_DMD_LONGNAME, "GRASS Vectors (5.7+)" );
     poDriver->SetMetadataItem( GDAL_DMD_HELPTOPIC, "drivers/vector/grass.html" );
 
+    poDriver->pfnOpen = GRASSDatasetOpen;
+
     GetGDALDriverManager()->RegisterDriver(poDriver);
 }