diff --git a/tests/observable.lua b/tests/observable.lua
index f417cd9..e041a6e 100644
--- a/tests/observable.lua
+++ b/tests/observable.lua
@@ -171,4 +171,5 @@ describe('Observable', function()
   dofile('tests/skip.lua')
   dofile('tests/skipUntil.lua')
   dofile('tests/take.lua')
+  dofile('tests/takeUntil.lua')
 end)
diff --git a/tests/takeUntil.lua b/tests/takeUntil.lua
new file mode 100644
index 0000000..9d0aaf9
--- /dev/null
+++ b/tests/takeUntil.lua
@@ -0,0 +1,45 @@
+describe('takeUntil', function()
+  it('produces an error if its parent errors', function()
+    local observable = Rx.Observable.fromValue(''):map(function(x) return x() end)
+    expect(observable.subscribe).to.fail()
+    expect(observable:takeUntil().subscribe).to.fail()
+  end)
+
+  it('fails if the first argument is not an Observable', function()
+    local observable = Rx.Observable.fromValue(3)
+    expect(observable:takeUntil(nil)).to.fail()
+    expect(observable:takeUntil(0)).to.fail()
+    expect(observable:takeUntil({})).to.fail()
+  end)
+
+  it('produces all values if the specified observable does not produce any values', function()
+    local trigger = Rx.Observable.create(function() end)
+    local observable = Rx.Observable.fromTable({2, 3, 4}):takeUntil(trigger)
+    expect(observable).to.produce(2, 3, 4)
+  end)
+
+  it('produces values after the specified observable produces a value', function()
+    local onNext = spy()
+    local trigger = Rx.Subject.create()
+    local subject = Rx.Subject.create()
+    subject:takeUntil(trigger):subscribe(Rx.Observer.create(onNext))
+    subject:onNext('a')
+    subject:onNext('b')
+    trigger:onNext('a')
+    subject:onNext('c')
+    subject:onNext('d')
+    subject:onComplete()
+    expect(onNext).to.equal({{'a'}, {'b'}})
+  end)
+
+  it('produces no values if the specified observable fires immediately', function()
+    local onNext = spy()
+    local subject = Rx.Subject.create()
+    subject:takeUntil(Rx.Observable.fromValue(1)):subscribe(Rx.Observer.create(onNext))
+    subject:onNext(1)
+    subject:onNext(2)
+    subject:onNext(3)
+    subject:onComplete()
+    expect(onNext).to.equal({})
+  end)
+end)