diff --git a/configure.ac b/configure.ac
index 36ab379..d769d2d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -101,7 +101,7 @@ PKG_CHECK_MODULES([ucto], [ucto >= 0.9.4] )
 CXXFLAGS="$ucto_CFLAGS $CXXFLAGS"
 LIBS="$ucto_LIBS $LIBS"
 
-PKG_CHECK_MODULES([folia], [folia >= 2.19] )
+PKG_CHECK_MODULES([folia], [folia >= 2.21] )
 CXXFLAGS="$folia_CFLAGS $CXXFLAGS"
 LIBS="$folia_LIBS $LIBS"
 
diff --git a/src/FoLiA-pm.cxx b/src/FoLiA-pm.cxx
index af68af2..45d21bd 100644
--- a/src/FoLiA-pm.cxx
+++ b/src/FoLiA-pm.cxx
@@ -393,12 +393,7 @@ Paragraph *add_par( Division *root, xmlNode *p, list<Note*>& notes ){
 	  note = new Note( args, doc );
 	}
 	else {
-	  if ( !isNCName( ref ) ){
-	    ref = "v." + ref;
-	    if ( !isNCName( ref ) ){
-	      throw ( "the ref attribute in note cannot be converted to an ID" );
-	    }
-	  }
+	  ref = create_NCName( ref );
 	  KWargs args;
 	  args["xml:id"] = ref;
 	  note = new Note( args, doc );
diff --git a/src/FoLiA-txt.cxx b/src/FoLiA-txt.cxx
index 7121d04..30b5266 100644
--- a/src/FoLiA-txt.cxx
+++ b/src/FoLiA-txt.cxx
@@ -114,16 +114,9 @@ bool handle_one_file( const string& fileName ){
   if ( !outputDir.empty() ){
     nameNoExt = docid;
   }
-  if ( !isNCName( docid ) ){
-    docid = "doc-" + docid;
-    if ( !isNCName( docid ) ){
-      cerr << "unable to generate a Document ID from the filename: '"
-	   << fileName << "'" << endl;
-      return false;
-    }
-  }
   Document *d = 0;
   try {
+    docid = create_NCName( docid );
     d = new Document( "xml:id='"+ docid + "'" );
   }
   catch ( exception& e ){