diff --git a/pygal/graph/graph.py b/pygal/graph/graph.py
index 28ec526..abd3118 100644
--- a/pygal/graph/graph.py
+++ b/pygal/graph/graph.py
@@ -92,7 +92,7 @@ class Graph(BaseGraph):
         a = self.svg.node(self.nodes['tooltip'], 'a')
         self.svg.node(a, 'rect',
                       id="tooltip-box",
-                      rx=5, ry=5,
+                      rx=5, ry=5, width=0, height=0
         )
         text = self.svg.node(a, 'text', class_='text')
         self.svg.node(text, 'tspan', class_='label')