diff --git a/parser-typechecker/src/Unison/Builtin.hs b/parser-typechecker/src/Unison/Builtin.hs
index 0704ed5ec..ca165705c 100644
--- a/parser-typechecker/src/Unison/Builtin.hs
+++ b/parser-typechecker/src/Unison/Builtin.hs
@@ -59,8 +59,8 @@ builtins = Map.fromList $
       , ("Int64.>=", "Int64 -> Int64 -> Boolean")
       , ("Int64.==", "Int64 -> Int64 -> Boolean")
       , ("Int64.increment", "Int64 -> Int64")
-      , ("Int64.isEven", "Int64 -> Boolean")
-      , ("Int64.isOdd", "Int64 -> Boolean")
+      , ("Int64.is-even", "Int64 -> Boolean")
+      , ("Int64.is-odd", "Int64 -> Boolean")
       , ("Int64.signum", "Int64 -> Int64")
       , ("Int64.negate", "Int64 -> Int64")
 
@@ -75,8 +75,8 @@ builtins = Map.fromList $
       , ("UInt64.>=", "UInt64 -> UInt64 -> Boolean")
       , ("UInt64.==", "UInt64 -> UInt64 -> Boolean")
       , ("UInt64.increment", "UInt64 -> UInt64")
-      , ("UInt64.isEven", "UInt64 -> Boolean")
-      , ("UInt64.isOdd", "UInt64 -> Boolean")
+      , ("UInt64.is-even", "UInt64 -> Boolean")
+      , ("UInt64.is-odd", "UInt64 -> Boolean")
 
       , ("Float.+", "Float -> Float -> Float")
       , ("Float.-", "Float -> Float -> Float")
@@ -103,11 +103,12 @@ builtins = Map.fromList $
       , ("Text.>", "Text -> Text -> Boolean")
 
       , ("Stream.empty", "forall a . Stream a")
+      , ("Stream.from-int64", "Int64 -> Stream Int64")
       , ("Stream.cons", "forall a . a -> Stream a -> Stream a")
       , ("Stream.take", "forall a . UInt64 -> Stream a -> Stream a")
       , ("Stream.drop", "forall a . UInt64 -> Stream a -> Stream a")
       , ("Stream.map", "forall a b . (a -> b) -> Stream a -> Stream b")
-      , ("Stream.foldLeft", "forall a b . b -> (b -> a -> b) -> Stream a -> b")
+      , ("Stream.fold-left", "forall a b . b -> (b -> a -> b) -> Stream a -> b")
 
       , ("Sequence.empty", "forall a . Sequence a")
       , ("Sequence.cons", "forall a . a -> Sequence a -> Sequence a")
diff --git a/runtime-jvm/main/src/main/scala/Builtins.scala b/runtime-jvm/main/src/main/scala/Builtins.scala
index f9f2dc5c0..c96da7326 100644
--- a/runtime-jvm/main/src/main/scala/Builtins.scala
+++ b/runtime-jvm/main/src/main/scala/Builtins.scala
@@ -22,7 +22,7 @@ object Builtins {
 
   // Stream.fromInt : Integer -> Stream Integer
   val Stream_fromInt = // Stream.iterate(unison 0)(Integer_inc)
-    fp_z("Stream.fromInt", "n", Stream.fromUnison)
+    fp_z("Stream.from-int64", "n", Stream.fromUnison)
 
   // Stream.cons : a -> Stream a -> Stream a
   val Stream_cons =
@@ -45,7 +45,7 @@ object Builtins {
 
   // Stream.foldLeft : b -> (b -> a -> b) -> Stream a -> b
   val Stream_foldLeft =
-    fppp_p("Stream.foldLeft", "acc", "f", "stream",
+    fppp_p("Stream.fold-left", "acc", "f", "stream",
            (acc: Value, f: Value, s: Stream[Value]) =>
              s.foldLeft(acc)(
                UnisonToScala.toUnboxed2(f.asInstanceOf[Lambda])(env))
diff --git a/unison-src/test1.u b/unison-src/test1.u
index 02574f10b..12195535b 100644
--- a/unison-src/test1.u
+++ b/unison-src/test1.u
@@ -8,4 +8,15 @@ Optional.isEmpty o = case o of
 
 increment x = x +_UInt64 1
 
-increment 3
+(|>) : forall a . a -> (a -> b) -> b
+a |> f = f a
+
+{-
+Stream.from-int64 -3
+  |> Stream.take 10
+  |> Stream.fold-left 0 (+_Int64)
+  |> Optional.Some
+  |> Optional.isEmpty
+-}
+
+Optional.Some 1