diff --git a/loopy/kernel/tools.py b/loopy/kernel/tools.py
index 95c3c336c4aeb78efb3a8dccfbdbc554103fdef1..b8be6191d933899dbac2f37eb5b85267defa7690 100644
--- a/loopy/kernel/tools.py
+++ b/loopy/kernel/tools.py
@@ -1241,7 +1241,7 @@ def draw_dependencies_as_unicode_arrows(
         for dep in insn.depends_on:
             reverse_deps.setdefault(dep, set()).add(insn.id)
 
-    # mapping of (from_id, to_id) tuples to column_index
+    # mapping of to_id tuples to column_index
     dep_to_column = {}
 
     # {{{ find column assignments
@@ -1318,7 +1318,7 @@ def draw_dependencies_as_unicode_arrows(
 
             elif insn.id in starts:
                 starts.remove(insn.id)
-                if starts:
+                if starts or pointed_at_insn_id not in processed_ids:
                     # will continue downward
                     row[col] = do_flag_downward(u"├", pointed_at_insn_id)
 
diff --git a/test/test_loopy.py b/test/test_loopy.py
index accf9c1dff5a1f660871dd63d6af3337aced6490..38d1cd6b0e5f2e9ccd64c6ddb41b161040e515e4 100644
--- a/test/test_loopy.py
+++ b/test/test_loopy.py
@@ -2908,6 +2908,25 @@ def test_dep_cycle_printing_and_error():
         print(lp.generate_code(knl)[0])
 
 
+def test_backwards_dep_printing_and_error():
+    knl = lp.make_kernel(
+            "{[i]: 0<=i<n}",
+            """
+            c[i] = a[i] + b[i]                       {id=insn1}
+            c[i] = 2*c[i]                            {id=insn2, dep=insn1}
+            c[i] = 7*c[i] + a[i]*a[i] + b[i]*b[i]    {id=insn3, dep=insn2}
+            b[i] = b[i] + c[i]                                 {id=insn4, dep=insn3}
+            d[i] = 7*a[i ]                                     {id=insn5, dep=insn4}
+            a[i] = a[i] + d[i]                                 {id=insn6, dep=insn5}
+            """, [
+                lp.GlobalArg('a, b', dtype=np.float64),
+                "..."
+            ])
+
+    # Used to crash with KeyError
+    print(knl)
+
+
 if __name__ == "__main__":
     if len(sys.argv) > 1:
         exec(sys.argv[1])