diff --git a/libs/microbit/core.cpp b/libs/microbit/core.cpp
index 2ef9de04..4a8969eb 100644
--- a/libs/microbit/core.cpp
+++ b/libs/microbit/core.cpp
@@ -166,6 +166,7 @@ namespace Array_ {
     int removeElement(RefCollection *c, uint32_t x) { return c->removeElement(x); }
 }
 
+
 // Import some stuff directly
 namespace pxt {
   //%
@@ -181,10 +182,12 @@ namespace pxt {
   //%
   Action mkAction(int reflen, int totallen, int startptr);
   //%
-  RefRecord* mkRecord(int reflen, int totallen);
-  //%
   RefRecord* mkClassInstance(int offset);
   //%
+  void RefRecord_destroy(RefRecord *r);
+  //%
+  void RefRecord_print(RefRecord *r);
+  //%
   void debugMemLeaks();
   //%
   int incr(uint32_t e);
diff --git a/pxtarget.json b/pxtarget.json
index 1100fcb7..d021d8eb 100644
--- a/pxtarget.json
+++ b/pxtarget.json
@@ -91,7 +91,7 @@
         "yottaTarget": "bbc-microbit-classic-gcc",
         "yottaCorePackage": "pxt-microbit-core",
         "githubCorePackage": "microsoft/pxt-microbit-core",
-        "gittag": "v0.4.4",
+        "gittag": "v0.5.0",
         "serviceId": "ws"
     },
     "serial": {
@@ -147,4 +147,4 @@
         "userVoiceApiKey": "WEkkIGaj1WtJnSUF59iwaA",
         "userVoiceForumId": 402381
     }
-}
\ No newline at end of file
+}