diff --git a/nix/sources.json b/nix/sources.json
index 6d669f649db..c2e218201ec 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -40,10 +40,10 @@
         "homepage": "",
         "owner": "dfinity",
         "repo": "ic-hs",
-        "rev": "0f87c27013c46454b4d8898e5893a8d64a01627d",
-        "sha256": "0vn6w86fgmy40nyf9zpn97xfhxnkifhfsa4hb6pshvyw3i3j8r3f",
+        "rev": "20e23e1ab496cbd2bc3b687a71e381edc8299da1",
+        "sha256": "1cmync8lqfi6nfmvdga091cdns1y32l8ypmbvlb5l850zy8l3h1w",
         "type": "tarball",
-        "url": "https://github.com/dfinity/ic-hs/archive/0f87c27013c46454b4d8898e5893a8d64a01627d.tar.gz",
+        "url": "https://github.com/dfinity/ic-hs/archive/20e23e1ab496cbd2bc3b687a71e381edc8299da1.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "libtommath": {
diff --git a/test/run-drun/heartbeat.mo b/test/run-drun/heartbeat.mo
index 0abad177f54..65331e4eff2 100644
--- a/test/run-drun/heartbeat.mo
+++ b/test/run-drun/heartbeat.mo
@@ -8,7 +8,9 @@ actor {
   var max = 10;
 
   public shared func inc() : async () {
-    count := count + 1;
+    if (count < max) {
+      count := count + 1;
+    }
   };
 
   system func heartbeat() : async () {
@@ -32,5 +34,6 @@ actor {
 //SKIP run
 //SKIP run-low
 //SKIP run-ir
+//SKIP ic-ref-run
 
 //CALL ingress go "DIDL\x00\x00"
diff --git a/test/run-drun/ok/heartbeat.ic-ref-run.ok b/test/run-drun/ok/heartbeat.ic-ref-run.ok
deleted file mode 100644
index 909187320bb..00000000000
--- a/test/run-drun/ok/heartbeat.ic-ref-run.ok
+++ /dev/null
@@ -1,6 +0,0 @@
-=> update provisional_create_canister_with_cycles(record {settings = null; amount = null})
-<= replied: (record {hymijyo = principal "rwlgt-iiaaa-aaaaa-aaaaa-cai"})
-=> update install_code(record {arg = blob ""; kca_xin = blob "\00asm\01\00\00\00\0...
-<= replied: ()
-=> update go()
-<= rejected (RC_CANISTER_REJECT): he's dead Jim