diff --git a/lib/cylc/config.py b/lib/cylc/config.py
index f2f3fcad01a..6004bcdaea9 100644
--- a/lib/cylc/config.py
+++ b/lib/cylc/config.py
@@ -1254,8 +1254,14 @@ def process_graph_line( self, line, section, ttype, seq, offset_seq_map,
 
                 if not self.validation and not graphing_disabled:
                     # edges not needed for validation
-                    self.generate_edges( lexpression, pruned_left_nodes,
-                                         right_name, ttype,
+                    left_edge_nodes = pruned_left_nodes
+                    right_edge_node = right_name
+                    if not left_edge_nodes and left_nodes:
+                        # All the left nodes have been pruned.
+                        left_edge_nodes = [right_name]
+                        right_edge_node = None
+                    self.generate_edges( lexpression, left_edge_nodes,
+                                         right_edge_node, ttype,
                                          seq, suicide )
                 self.generate_taskdefs( orig_line, pruned_left_nodes,
                                         right_name, ttype,
diff --git a/tests/cyclers/29-back_comp_start_up_simple.t b/tests/cyclers/29-back_comp_start_up_simple.t
new file mode 120000
index 00000000000..6b344bc8bb5
--- /dev/null
+++ b/tests/cyclers/29-back_comp_start_up_simple.t
@@ -0,0 +1 @@
+00-daily.t
\ No newline at end of file
diff --git a/tests/cyclers/back_comp_start_up_simple/graph.plain.ref b/tests/cyclers/back_comp_start_up_simple/graph.plain.ref
new file mode 100644
index 00000000000..2415c2485c7
--- /dev/null
+++ b/tests/cyclers/back_comp_start_up_simple/graph.plain.ref
@@ -0,0 +1,7 @@
+edge "cold_foo.2014090100" "foo.2014090100" solid black
+graph 
+node "cold_foo.2014090100" "cold_foo\n2014090100" unfilled box black lightgrey
+node "foo.2014090100" "foo\n2014090100" unfilled box black lightgrey
+node "foo.2014090106" "foo\n2014090106" unfilled box black lightgrey
+node "foo.2014090112" "foo\n2014090112" unfilled box black lightgrey
+stop
diff --git a/tests/cyclers/back_comp_start_up_simple/reference.log b/tests/cyclers/back_comp_start_up_simple/reference.log
new file mode 100644
index 00000000000..428afb3ec3b
--- /dev/null
+++ b/tests/cyclers/back_comp_start_up_simple/reference.log
@@ -0,0 +1,29 @@
+2014-08-18T12:19:43+01 INFO - port:7766
+2014-08-18T12:19:43+01 INFO - Suite starting at 2014-08-18T12:19:43+01
+2014-08-18T12:19:43+01 INFO - Log event clock: real time
+2014-08-18T12:19:43+01 INFO - Run mode: live
+2014-08-18T12:19:43+01 INFO - Initial point: 2014090100
+2014-08-18T12:19:43+01 INFO - Final point: 2014090112
+2014-08-18T12:19:43+01 INFO - Cold Start 2014090100
+2014-08-18T12:19:43+01 INFO - [cold_foo.2014090100] -triggered off []
+2014-08-18T12:19:44+01 INFO - [cold_foo.2014090100] -submit_method_id=7693
+2014-08-18T12:19:44+01 INFO - [cold_foo.2014090100] -submission succeeded
+2014-08-18T12:19:44+01 INFO - [cold_foo.2014090100] -(current:submitted)> cold_foo.2014090100 started at 2014-08-18T12:19:43+01
+2014-08-18T12:19:51+01 INFO - [cold_foo.2014090100] -(current:running)> cold_foo.2014090100 succeeded at 2014-08-18T12:19:50+01
+2014-08-18T12:19:52+01 INFO - [foo.2014090100] -triggered off ['cold_foo.2014090100']
+2014-08-18T12:19:53+01 INFO - [foo.2014090100] -submit_method_id=7808
+2014-08-18T12:19:53+01 INFO - [foo.2014090100] -submission succeeded
+2014-08-18T12:19:53+01 INFO - [foo.2014090100] -(current:submitted)> foo.2014090100 started at 2014-08-18T12:19:52+01
+2014-08-18T12:19:54+01 INFO - [foo.2014090106] -triggered off []
+2014-08-18T12:19:55+01 INFO - [foo.2014090106] -submit_method_id=7910
+2014-08-18T12:19:55+01 INFO - [foo.2014090106] -submission succeeded
+2014-08-18T12:19:55+01 INFO - [foo.2014090106] -(current:submitted)> foo.2014090106 started at 2014-08-18T12:19:55+01
+2014-08-18T12:19:56+01 INFO - [foo.2014090112] -triggered off []
+2014-08-18T12:19:57+01 INFO - [foo.2014090112] -submit_method_id=8015
+2014-08-18T12:19:57+01 INFO - [foo.2014090112] -submission succeeded
+2014-08-18T12:19:57+01 INFO - [foo.2014090118] -holding (beyond suite stop point) 2014090112
+2014-08-18T12:19:57+01 INFO - [foo.2014090112] -(current:submitted)> foo.2014090112 started at 2014-08-18T12:19:57+01
+2014-08-18T12:19:58+01 INFO - [foo.2014090100] -(current:running)> foo.2014090100 succeeded at 2014-08-18T12:19:57+01
+2014-08-18T12:20:04+01 INFO - [foo.2014090112] -(current:running)> foo.2014090112 succeeded at 2014-08-18T12:20:03+01
+2014-08-18T12:20:09+01 INFO - [foo.2014090106] -(current:running)> foo.2014090106 succeeded at 2014-08-18T12:20:09+01
+2014-08-18T12:20:10+01 INFO - Suite shutting down at 2014-08-18T12:20:10+01
diff --git a/tests/cyclers/back_comp_start_up_simple/suite.rc b/tests/cyclers/back_comp_start_up_simple/suite.rc
new file mode 100644
index 00000000000..ed2ee99b5e0
--- /dev/null
+++ b/tests/cyclers/back_comp_start_up_simple/suite.rc
@@ -0,0 +1,11 @@
+[scheduling]
+    initial cycle time = 2014090100
+    final cycle time = 2014090112
+    [[special tasks]]
+        start-up = cold_foo
+    [[dependencies]]
+        [[[0,6,12,18]]]
+            graph = cold_foo => foo
+[visualization]
+    initial cycle time = 2014090100
+    final cycle time = 2014090112