X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=scm%2Fgraphviz.scm;h=657fdb23b3e00e5233c583ad8b31bd19ea4c4c84;hb=0ccac4adf83c431b5d1c89bebfd6a916369328dd;hp=61fa5b1e1b7c3158f97864068cd8eeb6d6f939fe;hpb=8ef5f99e63cc9e52c7c0071cde4d99e057d10329;p=lilypond.git

diff --git a/scm/graphviz.scm b/scm/graphviz.scm
index 61fa5b1e1b..657fdb23b3 100644
--- a/scm/graphviz.scm
+++ b/scm/graphviz.scm
@@ -69,7 +69,9 @@
               es)
     (for-each (lambda (c)
                 (format out "subgraph cluster_~a {\nlabel= \"~a\"\ncolor=blue\n"
-                        (string-filter (car c) char-alphabetic?)
+                        (if (guile-v2)
+                            (string-filter char-alphabetic? (car c))
+                            (string-filter (car c) char-alphabetic?))
                         (car c))
                 (for-each (lambda (n) (format out "~a\n" n)) (cdr c))
                 (display "}\n" out))