diff --git a/src/meshlabplugins/filter_create/filter_create.cpp b/src/meshlabplugins/filter_create/filter_create.cpp
index d6f1762fd..018b737ed 100644
--- a/src/meshlabplugins/filter_create/filter_create.cpp
+++ b/src/meshlabplugins/filter_create/filter_create.cpp
@@ -174,7 +174,7 @@ RichParameterList FilterCreate::initParameterList(const QAction *action, const M
 		  )));
 		break;
 	default :
-		assert(0);
+		;
 	}
 	return parlst;
 }
diff --git a/src/meshlabplugins/filter_texture_defragmentation/filter_texture_defragmentation.cpp b/src/meshlabplugins/filter_texture_defragmentation/filter_texture_defragmentation.cpp
index be2a978cf..9f540b28a 100644
--- a/src/meshlabplugins/filter_texture_defragmentation/filter_texture_defragmentation.cpp
+++ b/src/meshlabplugins/filter_texture_defragmentation/filter_texture_defragmentation.cpp
@@ -112,6 +112,17 @@ int FilterTextureDefragPlugin::getRequirements(const QAction *a)
 	return MeshModel::MM_NONE;
 }
 
+bool FilterTextureDefragPlugin::requiresGLContext(const QAction* a) const
+{
+	switch (ID(a)) {
+	case FP_TEXTURE_DEFRAG:
+		return true;
+	default:
+		assert(0);
+		return false;
+	}
+}
+
 int FilterTextureDefragPlugin::postCondition(const QAction *a) const
 {
 	switch (ID(a)) {
diff --git a/src/meshlabplugins/filter_texture_defragmentation/filter_texture_defragmentation.h b/src/meshlabplugins/filter_texture_defragmentation/filter_texture_defragmentation.h
index 82203bec8..9391b5747 100644
--- a/src/meshlabplugins/filter_texture_defragmentation/filter_texture_defragmentation.h
+++ b/src/meshlabplugins/filter_texture_defragmentation/filter_texture_defragmentation.h
@@ -59,6 +59,7 @@ class FilterTextureDefragPlugin : public QObject, public FilterPlugin
 			unsigned int& postConditionMask,
 			vcg::CallBackPos * cb);
 	virtual int getRequirements(const QAction*);
+	bool requiresGLContext(const QAction*) const;
 	virtual int getPreConditions(const QAction*) const;
 	virtual int postCondition(const QAction* ) const;
 	FilterClass getClass(const QAction *a) const;