diff --git a/britney2/installability/tester.py b/britney2/installability/tester.py
index 79fe1d3..e178ca7 100644
--- a/britney2/installability/tester.py
+++ b/britney2/installability/tester.py
@@ -300,9 +300,9 @@ class InstallabilityTester(object):
             if t.architecture not in self._cache_ess:
                 # The minimal essential set cache is not present -
                 # compute it now.
-                (start, ess_never) = self._get_min_pseudo_ess_set(t.architecture)
+                (start, ess_never, ess_choices) = self._get_min_pseudo_ess_set(t.architecture)
             else:
-                (start, ess_never) = self._cache_ess[t.architecture]
+                (start, ess_never, ess_choices) = self._cache_ess[t.architecture]
 
             if t in ess_never:
                 # t conflicts with something in the essential set or the essential
@@ -313,6 +313,7 @@ class InstallabilityTester(object):
                 return False
             musts.update(start)
             never.update(ess_never)
+            choices.update(ess_choices)
 
         # curry check_loop
         check_loop = partial(self._check_loop, universe, testing,
@@ -630,7 +631,7 @@ class InstallabilityTester(object):
 
             for x in start:
                 ess_never.update(universe[x][1])
-            self._cache_ess[arch] = (frozenset(start), frozenset(ess_never))
+            self._cache_ess[arch] = (frozenset(start), frozenset(ess_never), frozenset(ess_choices))
 
         return self._cache_ess[arch]
 
diff --git a/tests/test_inst_tester.py b/tests/test_inst_tester.py
index a8536d8..b18e858 100644
--- a/tests/test_inst_tester.py
+++ b/tests/test_inst_tester.py
@@ -49,6 +49,31 @@ class TestInstTester(unittest.TestCase):
         universe.add_testing_binary(pkg_awk)
         assert universe.is_installable(pkg_lintian)
 
+    def test_basic_essential_conflict(self):
+        builder = new_pkg_universe_builder()
+        pseudo_ess1 = builder.new_package('pseudo-essential1')
+        pseudo_ess2 = builder.new_package('pseudo-essential2')
+        essential_simple = builder.new_package('essential-simple').is_essential()
+        essential_with_deps = builder.new_package('essential-with-deps').is_essential().\
+            depends_on_any_of(pseudo_ess1, pseudo_ess2)
+        conflict1 = builder.new_package('conflict1').conflicts_with(essential_simple)
+        conflict2 = builder.new_package('conflict2').conflicts_with(pseudo_ess1, pseudo_ess2)
+        conflict_installable1 = builder.new_package('conflict-inst1').conflicts_with(pseudo_ess1)
+        conflict_installable2 = builder.new_package('conflict-inst2').conflicts_with(pseudo_ess2)
+
+        universe = builder.build()
+
+        assert universe.is_installable(essential_simple.pkg_id)
+        assert universe.is_installable(essential_with_deps.pkg_id)
+        assert universe.is_installable(conflict_installable1.pkg_id)
+        assert universe.is_installable(conflict_installable2.pkg_id)
+        assert not universe.is_installable(conflict1.pkg_id)
+        assert not universe.is_installable(conflict2.pkg_id)
+
+        for line in universe.stats.stats():
+            print(line)
+        assert universe.stats.conflicts_essential == 1
+
     def test_basic_simple_choice(self):
         builder = new_pkg_universe_builder()
         root_pkg = builder.new_package('root')