diff --git a/.github/workflows/typeguard.yml b/.github/workflows/typeguard.yml
index d3c1da10e..1c1b3d350 100644
--- a/.github/workflows/typeguard.yml
+++ b/.github/workflows/typeguard.yml
@@ -1,8 +1,9 @@
 name: typeguard
 
-# TODO: enable this once typeguard=4 is released and issues are fixed.
-# on:
-#   - push
+on:
+  pull_request:
+  push:
+    branches: [main]
 
 jobs:
   typeguard:
diff --git a/pyproject.toml b/pyproject.toml
index f0ea8eddf..16f503ef5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -55,7 +55,7 @@ testing = [
     "pytest-randomly",
     "pytest-timeout",
     "pre_commit",
-    "typeguard",
+    "typeguard>=4.0.0",
 ]
 
 [project.urls]