diff --git a/plugins/yjs/fps_yjs/ywidgets/widgets.py b/plugins/yjs/fps_yjs/ywidgets/widgets.py
index 52eeae03..d5d7f4c2 100644
--- a/plugins/yjs/fps_yjs/ywidgets/widgets.py
+++ b/plugins/yjs/fps_yjs/ywidgets/widgets.py
@@ -1,15 +1,15 @@
 import sys
 from typing import Any
 
-from pycrdt import TransactionEvent
-
 try:
-    from ypywidgets.utils import (  # type: ignore
+    import ypywidgets  # noqa: F401
+    from pycrdt import (
+        TransactionEvent,
         YMessageType,
         YSyncMessageType,
+        create_sync_message,
         create_update_message,
-        process_sync_message,
-        sync,
+        handle_sync_message,
     )
     ypywidgets_installed = True
 except ImportError:
@@ -41,15 +41,15 @@ def comm_open(self, msg, comm) -> None:
             self.comm = comm
             model = self.ydocs[f"{name}Model"]()
             self.widgets[comm_id] = {"model": model, "comm": comm}
-            msg = sync(model.ydoc)
-            comm.send(**msg)
+            msg = create_sync_message(model.ydoc)
+            comm.send(buffers=[msg])
 
         def comm_msg(self, msg) -> None:
             comm_id = msg["content"]["comm_id"]
             message = bytes(msg["buffers"][0])
             if message[0] == YMessageType.SYNC:
                 ydoc = self.widgets[comm_id]["model"].ydoc
-                reply = process_sync_message(
+                reply = handle_sync_message(
                     message[1:],
                     ydoc,
                 )
diff --git a/pyproject.toml b/pyproject.toml
index 15643c82..297a424d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -54,7 +54,7 @@ test = [
     "requests",
     "websockets",
     "ipykernel",
-    "ypywidgets >=0.9.1,<0.10.0",
+    "ypywidgets >=0.9.3,<0.10.0",
     "ypywidgets-textual >=0.5.0,<0.6.0",
 ]
 docs = [ "mkdocs", "mkdocs-material" ]
diff --git a/tests/test_execute.py b/tests/test_execute.py
index e45e700c..d423f1a1 100644
--- a/tests/test_execute.py
+++ b/tests/test_execute.py
@@ -55,7 +55,6 @@ async def recv(self) -> bytes:
         return bytes(b)
 
 
-@pytest.mark.skip(reason="FIXME: caused by new ypywidgets version")
 @pytest.mark.asyncio
 @pytest.mark.parametrize("auth_mode", ("noauth",))
 async def test_execute(auth_mode, unused_tcp_port):
diff --git a/tests/test_server.py b/tests/test_server.py
index 0ba0cc03..66a986d4 100644
--- a/tests/test_server.py
+++ b/tests/test_server.py
@@ -106,8 +106,8 @@ async def test_rest_api(start_jupyverse):
         cells = json.loads(str(ycells))
         assert cells[0]["outputs"] == [
             {
-                "data": {"text/plain": ["3"]},
-                "execution_count": 1.0,
+                "data": {"text/plain": "3"},
+                "execution_count": 1,
                 "metadata": {},
                 "output_type": "execute_result",
             }
@@ -117,8 +117,8 @@ async def test_rest_api(start_jupyverse):
         ]
         assert cells[2]["outputs"] == [
             {
-                "data": {"text/plain": ["7"]},
-                "execution_count": 3.0,
+                "data": {"text/plain": "7"},
+                "execution_count": 3,
                 "metadata": {},
                 "output_type": "execute_result",
             }