diff --git a/e2e/assets/counter_idl_mo/counter_idl.mo b/e2e/assets/counter_idl_mo/counter_idl.mo
index b44f4f4398..423b284842 100644
--- a/e2e/assets/counter_idl_mo/counter_idl.mo
+++ b/e2e/assets/counter_idl_mo/counter_idl.mo
@@ -1,3 +1,6 @@
+import A "mo:stdlib/array.mo";
+import Prim "mo:prim";
+
 type List<T> = ?{head : T; tail : List<T>};
 type List2<T> = { #nil; #cons: (T, List2<T>) };
 
@@ -15,7 +18,7 @@ actor {
          }
     };
     public func inc(i: Int, b: Bool, str: Text, vec: [Nat], l: List<Int>, l2: List2<Int>) : async (Int, Bool, Text, [Nat], List<Int>, List2<Int>) {
-        let arr = Array_tabulate<Nat>(
+        let arr = A.tabulate<Nat>(
           vec.len(),
           func (i : Nat) : Nat {
               vec[i]+1;
@@ -23,8 +26,8 @@ actor {
 
         var text = "";
         for (c in str.chars()) {
-            let c2 = word32ToChar(charToWord32(c)+1);
-            text := text # charToText(c2);
+            let c2 = Prim.word32ToChar(Prim.charToWord32(c)+1);
+            text := text # Prim.charToText(c2);
         };
         return (i+1, not b, text, arr, map(l), map2(l2));
     };
diff --git a/e2e/assets/print_mo/print.mo b/e2e/assets/print_mo/print.mo
index 604c56f1f9..49b5b7d701 100644
--- a/e2e/assets/print_mo/print.mo
+++ b/e2e/assets/print_mo/print.mo
@@ -1,5 +1,7 @@
+import Debug "mo:stdlib/debug.mo";
+
 actor HelloActor {
   public func hello() : async () {
-    debugPrint("Hello, World! from DFINITY \n");
+    Debug.print("Hello, World! from DFINITY \n");
   }
 };
diff --git a/nix/sources.json b/nix/sources.json
index 2d85612080..b96f54a85a 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -26,7 +26,7 @@
     "motoko": {
         "ref": "master",
         "repo": "ssh://git@github.com/dfinity-lab/motoko",
-        "rev": "53723e64705f165025e89586607810a5787b05e7",
+        "rev": "4d6afaa511cd9ae62ad2bb6a3c9a0f79c818ab8d",
         "type": "git"
     },
     "napalm": {