diff --git a/src/meshlab/dialogs/save_mesh_attributes_dialog.cpp b/src/meshlab/dialogs/save_mesh_attributes_dialog.cpp
index 54c5cc9d1d..c473ebe335 100644
--- a/src/meshlab/dialogs/save_mesh_attributes_dialog.cpp
+++ b/src/meshlab/dialogs/save_mesh_attributes_dialog.cpp
@@ -280,7 +280,10 @@ bool SaveMeshAttributesDialog::shouldBeChecked(int bit, int /*capabilityBits*/,
 
 void SaveMeshAttributesDialog::updateMask()
 {
-	int newmask = 0;
+	// Edge connectivity is topology, not an optional per-element attribute, and
+	// therefore has no checkbox in this dialog. Preserve it when the exporter
+	// includes it in its default mask.
+	int newmask = defaultBits & vcg::tri::io::Mask::IOM_EDGEINDEX;
 
 	if( ui->check_iom_vertflags->isChecked()    ) { newmask |= vcg::tri::io::Mask::IOM_VERTFLAGS;}
 	if( ui->check_iom_vertcolor->isChecked()    ) { newmask |= vcg::tri::io::Mask::IOM_VERTCOLOR;}
@@ -319,4 +322,3 @@ void SaveMeshAttributesDialog::on_textureQualitySpinBox_valueChanged(int arg1)
 		ui->textureQualitySpinBox->setSuffix("");
 	}
 }
-
diff --git a/src/meshlabplugins/io_base/baseio.cpp b/src/meshlabplugins/io_base/baseio.cpp
index 6d0b962c0f..ecd0b17678 100644
--- a/src/meshlabplugins/io_base/baseio.cpp
+++ b/src/meshlabplugins/io_base/baseio.cpp
@@ -668,7 +668,7 @@ void BaseMeshIOPlugin::saveProject(
 void BaseMeshIOPlugin::exportMaskCapability(const QString &format, int &capability, int &defaultBits) const
 {
 	if (format.toUpper() == tr("PLY")) {
-		capability = tri::io::ExporterPLY<CMeshO>::GetExportMaskCapability();
+		capability = tri::io::ExporterPLY<CMeshO>::GetExportMaskCapability() | tri::io::Mask::IOM_EDGEINDEX;
 		// For the default bits of the ply format disable flags and normals that usually are not useful.
 		defaultBits = capability;
 		defaultBits &= (~tri::io::Mask::IOM_FLAGS);