Index: contrib/arch/hadlbppp.py
===================================================================
--- contrib/arch/hadlbppp.py	(revision c123609e8403988e0b6e37bddc1b78a6ea86203b)
+++ contrib/arch/hadlbppp.py	(revision c088fd4a0f5931862c58e36af784f67a36fb6109)
@@ -1727,4 +1727,5 @@
 		outf.write("\tlabel=\"%s\";\n" % arch['name'])
 		outf.write("\tcompound=true;\n")
+		outf.write("\tsplines=\"polyline\";\n")
 		outf.write("\tedge [fontsize=8];\n")
 		outf.write("\t\n")