diff --git a/types/baconjs/baconjs-tests.ts b/types/baconjs/baconjs-tests.ts
index b7d6db4c0f..4affe6805c 100644
--- a/types/baconjs/baconjs-tests.ts
+++ b/types/baconjs/baconjs-tests.ts
@@ -252,19 +252,20 @@ function CombiningMultipleStreamsAndProperties() {
 
     {
         // To calculate the current sum of three numeric Properties, you can do:
-        var property = Bacon.constant(1),
-            stream = Bacon.once(2),
+        // (NOTE: combineWith requires the first type argument to be ErrorEvent, but the constant
+        // and once methods default to unknown, so we're forced to manually specify it)
+        let property = Bacon.constant<ErrorEvent, number>(1),
+            stream = Bacon.once<ErrorEvent, number>(2),
             constant = 3;
-        // NOTE: had to explicitly specify the typing for `x:number, y:number, z:number`
-        Bacon.combineWith((x:number, y:number, z:number) => x + y + z, property, stream, constant);
+        Bacon.combineWith((x, y, z) => x + y + z, property, stream, constant);
     }
 
     {
         // Assuming you've got streams or properties named `password`, `username`, `firstname` and `lastname`, you can do:
-        var password = Bacon.constant("easy"),
-            username = Bacon.constant("juha"),
-            firstname = Bacon.constant("juha"),
-            lastname = Bacon.constant("paananen"),
+        let password = Bacon.constant<ErrorEvent, string>("easy"),
+            username = Bacon.constant<ErrorEvent, string>("juha"),
+            firstname = Bacon.constant<ErrorEvent, string>("juha"),
+            lastname = Bacon.constant<ErrorEvent, string>("paananen"),
         // NOTE: you should provide `combineTemplate` typing explicitly!
             loginInfo = Bacon.combineTemplate<string, {
                 magicNumber:number; userid:string; passwd:string;