1 files changed, 1 insertions, 1 deletions
diff --git a/graph.py b/graph.py
index 81a16ba..05f16c1 100644
--- a/graph.py
+++ b/graph.py
@@ -34,7 +34,7 @@ class DotBackend:
         self.graphname = graphname
         self.lines = []
         self._source = None
-        self.emit("digraph %s {" % graphname)
+        self.emit("digraph %s {" % normalize_node_id(graphname))
         if rankdir:
             self.emit('rankdir=%s' % rankdir)
         if ratio: