diff --git a/graph/formats/dot/testdata/Makefile b/graph/formats/dot/testdata/Makefile
index c3bfcb9b..876922fc 100644
--- a/graph/formats/dot/testdata/Makefile
+++ b/graph/formats/dot/testdata/Makefile
@@ -98,7 +98,7 @@ fetch: graphviz
 	rm -rf graphviz
 
 graphviz:
-	git clone https://github.com/ellson/graphviz.git
+	git clone --depth=1 https://github.com/ellson/graphviz.git
 
 clean:
 	rm -rf *.dot input output