--- a/hgext3rd/topic/stack.py	Sat Sep 09 22:32:44 2017 +0530
+++ b/hgext3rd/topic/stack.py	Thu Sep 07 19:43:07 2017 +0200
@@ -170,9 +170,13 @@
             prev = ctx.rev()
             continue
         p1 = ctx.p1()
+        p2 = ctx.p2()
         if p1.obsolete():
             p1 = repo[_singlesuccessor(repo, p1)]
-        if p1.rev() != prev and p1.node() != node.nullid:
+        if p2.node() != node.nullid:
+            entries.append((idxmap.get(p1.rev()), False, p1))
+            entries.append((idxmap.get(p2.rev()), False, p2))
+        elif p1.rev() != prev and p1.node() != node.nullid:
             entries.append((idxmap.get(p1.rev()), False, p1))
         entries.append((idx, True, ctx))
         idxmap[ctx.rev()] = idx

--- a/tests/test-topic-stack.t	Sat Sep 09 22:32:44 2017 +0530
+++ b/tests/test-topic-stack.t	Thu Sep 07 19:43:07 2017 +0200
@@ -627,6 +627,8 @@
   t2: c_B
     ^ c_A
   t1: c_H
+    ^ c_G
+    ^ c_D
   t0^ c_D (base)
   $ hg stack blue
   ### topic: blue (3 heads)
@@ -685,6 +687,7 @@
   ### topic: red (3 heads)
   ### branch: default, ambigious rebase destination
   t5$ c_H (unstable)
+    ^ c_G
     ^ c_D
   t4$ c_C (unstable)
   t1^ c_B (base)
@@ -758,6 +761,7 @@
   ### topic: red (3 heads)
   ### branch: default, ambigious rebase destination
   t5$ c_H (unstable)
+    ^ c_G
     ^ c_D
   t4$ c_F (unstable)
   t3$ c_E (unstable)