diff --git a/pycallgraph/output/output.py b/pycallgraph/output/output.py
index 662d5630..c2720d66 100644
--- a/pycallgraph/output/output.py
+++ b/pycallgraph/output/output.py
@@ -40,7 +40,7 @@ def edge_color(self, edge):
     def node_label(self, node):
         parts = [
             '{0.name}',
-            'calls: {0.calls.value:n}',
+            'calls: {0.calls.value:d}',
             'time: {0.time.value:f}s',
         ]