diff --git a/src/CoordinateOperation/CoordinateOperationParams.php b/src/CoordinateOperation/CoordinateOperationParams.php
index bdebd0b1b..57b50d77a 100644
--- a/src/CoordinateOperation/CoordinateOperationParams.php
+++ b/src/CoordinateOperation/CoordinateOperationParams.php
@@ -52657,6 +52657,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5SG1952NAD831986StGeorgeLongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8547' => [
             'Latitude difference file' => [
@@ -52667,6 +52672,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5SL1952NAD831986StLawrenceLongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8548' => [
             'Latitude difference file' => [
@@ -52677,6 +52687,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5SP1952NAD831986StPaulLongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8549' => [
             'Latitude difference file' => [
@@ -52687,6 +52702,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5NAD27NAD831986AlaskaLongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8550' => [
             'Latitude difference file' => [
@@ -52697,6 +52717,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5NAD831986NAD831992AlaskaLongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8551' => [
             'Latitude difference file' => [
@@ -52735,6 +52760,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5NAD27NAD831986CONUSLongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8556' => [
             'Latitude difference file' => [
@@ -52745,6 +52775,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5NAD831986NAD83HARNCONUSLongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8559' => [
             'Latitude difference file' => [
@@ -52769,6 +52804,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5OHDNAD831986HawaiiLongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8562' => [
         ],
@@ -52837,6 +52877,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5NAD831986NAD831993HawaiiLongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8661' => [
             'Latitude difference file' => [
@@ -52861,6 +52906,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5AS62NAD831993ASLongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8665' => [
             'Latitude difference file' => [
@@ -52871,6 +52921,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5GU63NAD831993GuamCnMILongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8668' => [
             'Latitude difference file' => [
@@ -52881,6 +52936,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5PR40NAD831986PRVILongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8669' => [
             'Latitude difference file' => [
@@ -52891,6 +52951,11 @@ class CoordinateOperationParams
                 'reverses' => true,
                 'fileProvider' => 'PHPCoord\\CoordinateOperation\\NADCON5NAD831986NAD831993PRVILongitudeProvider',
             ],
+            'Ellipsoidal height difference file' => [
+                'value' => null,
+                'uom' => null,
+                'reverses' => false,
+            ],
         ],
         'urn:ogc:def:coordinateOperation:EPSG::8673' => [
             'Latitude difference file' => [
diff --git a/src/EPSG/Import/EPSGImporter.php b/src/EPSG/Import/EPSGImporter.php
index 2b92f8b5f..914ee1128 100644
--- a/src/EPSG/Import/EPSGImporter.php
+++ b/src/EPSG/Import/EPSGImporter.php
@@ -30,6 +30,7 @@
 use function min;
 use const PHP_EOL;
 use PHPCoord\CoordinateOperation;
+use PHPCoord\CoordinateOperation\CoordinateOperationMethods;
 use PHPCoord\CoordinateReferenceSystem\Compound;
 use PHPCoord\CoordinateReferenceSystem\Geocentric;
 use PHPCoord\CoordinateReferenceSystem\Geographic2D;
@@ -1567,6 +1568,9 @@ public function generateDataCoordinateOperations(SQLite3 $sqlite): void
                 $params[$paramsRow['name']] = $paramsRow;
                 unset($params[$paramsRow['name']]['name']);
             }
+            if (isset($operationData['method']) && $operationData['method'] === CoordinateOperationMethods::EPSG_NADCON5_2D) { // for PHP7.4 w/out named params
+                $params['Ellipsoidal height difference file'] = ['value' => null, 'uom' => null, 'reverses' => false];
+            }
             $paramData[$operation] = $params;
         }