diff --git a/conftest.py b/conftest.py
index 0b8ae523d7d..5ee456980de 100644
--- a/conftest.py
+++ b/conftest.py
@@ -73,6 +73,12 @@ def monkeypatch_plugin_test_packages(monkeypatch: pytest.MonkeyPatch) -> None:
         monkeypatch.syspath_prepend(os.path.abspath(os.path.relpath(path)))
 
 
+@pytest.fixture(scope="function")
+def session_params(session_params: t.Dict[str, t.Any]) -> t.Dict[str, t.Any]:
+    session_params.update({"x": 800, "y": 600})
+    return session_params
+
+
 @pytest.fixture(scope="function")
 def socket_name(request: pytest.FixtureRequest) -> str:
     return "tmuxp_test%s" % next(namer)
diff --git a/poetry.lock b/poetry.lock
index c62201854c5..a13b31d1ff1 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -561,14 +561,14 @@ i18n = ["Babel (>=2.7)"]
 
 [[package]]
 name = "libtmux"
-version = "0.19.1"
+version = "0.20.0"
 description = "Typed scripting library / ORM / API wrapper for tmux"
 category = "main"
 optional = false
 python-versions = ">=3.7,<4.0"
 files = [
-    {file = "libtmux-0.19.1-py3-none-any.whl", hash = "sha256:0ab6986772555bca58c03400317b340975afc4b0acf5e614992b5e8aedf31517"},
-    {file = "libtmux-0.19.1.tar.gz", hash = "sha256:614fea2b09ed344735b4da2fe35e763ca2087e89a73c39d3663ed7f515fae356"},
+    {file = "libtmux-0.20.0-py3-none-any.whl", hash = "sha256:885ea6415bca1f23f55d5bdd638625419483e749912919841752d9c57179afb0"},
+    {file = "libtmux-0.20.0.tar.gz", hash = "sha256:5a4dcc01c52888970c0d515d63c7559b702055d3f53bec716c6a7de48fe88dd3"},
 ]
 
 [[package]]
@@ -1707,4 +1707,4 @@ test = []
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.7"
-content-hash = "f7a4d54b648a94b51c269f80af6bd66a7b930e758be938b6733aa481d9db090d"
+content-hash = "b5f086b4a3ef354f56d4e9dbbef99a5aef9e50cbfd3ce1972df5111ecd173d32"
diff --git a/pyproject.toml b/pyproject.toml
index 79ce5ab1b15..c08225f3555 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -47,7 +47,7 @@ tmuxp = 'tmuxp:cli.cli'
 
 [tool.poetry.dependencies]
 python = "^3.7"
-libtmux = "~0.19.1"
+libtmux = "~0.20.0"
 colorama = ">=0.3.9"
 PyYAML = "^6.0"
 
diff --git a/src/tmuxp/workspace/builder.py b/src/tmuxp/workspace/builder.py
index 1af6026d6d8..efd2f2fc6aa 100644
--- a/src/tmuxp/workspace/builder.py
+++ b/src/tmuxp/workspace/builder.py
@@ -9,7 +9,7 @@
 import typing as t
 
 from libtmux._internal.query_list import ObjectDoesNotExist
-from libtmux.common import has_lt_version
+from libtmux.common import has_gte_version, has_lt_version
 from libtmux.pane import Pane
 from libtmux.server import Server
 from libtmux.session import Session
@@ -236,6 +236,9 @@ def build(self, session: t.Optional[Session] = None, append: bool = False) -> No
                     new_session_kwargs["start_directory"] = self.session_config[
                         "start_directory"
                     ]
+                if has_gte_version("2.6"):
+                    new_session_kwargs["x"] = 800
+                    new_session_kwargs["y"] = 600
                 session = self.server.new_session(
                     session_name=self.session_config["session_name"],
                     **new_session_kwargs,