diff --git a/pyproject.toml b/pyproject.toml
index 79b1d16..0355abb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -15,7 +15,7 @@ classifiers = [
 ]
 dependencies = [
     "google-cloud-logging>=3.11",
-    "python-json-logger>=3.1",
+    "python-json-logger>=4.2.0",
 ]
 
 [project.urls]
diff --git a/uv.lock b/uv.lock
index 761fea9..7cde932 100644
--- a/uv.lock
+++ b/uv.lock
@@ -68,7 +68,7 @@ dev = [
 [package.metadata]
 requires-dist = [
     { name = "google-cloud-logging", specifier = ">=3.11" },
-    { name = "python-json-logger", specifier = ">=3.1" },
+    { name = "python-json-logger", specifier = ">=4.2.0" },
 ]
 
 [package.metadata.requires-dev]
@@ -726,11 +726,11 @@ wheels = [
 
 [[package]]
 name = "python-json-logger"
-version = "4.1.0"
+version = "4.2.0"
 source = { registry = "https://pypi.org/simple" }
-sdist = { url = "https://files.pythonhosted.org/packages/f7/ff/3cc9165fd44106973cd7ac9facb674a65ed853494592541d339bdc9a30eb/python_json_logger-4.1.0.tar.gz", hash = "sha256:b396b9e3ed782b09ff9d6e4f1683d46c83ad0d35d2e407c09a9ebbf038f88195", size = 17573, upload-time = "2026-03-29T04:39:56.805Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/21/25/5473e46b179f8e8b4ad3aeeb36773d1701b7770eaf5e5bc2025c7303b598/python_json_logger-4.2.0.tar.gz", hash = "sha256:e371ebe22ec01e289850102091a2b1f6fc9e655c7f1f5f29073936756c290afa", size = 18211, upload-time = "2026-08-15T11:36:38.232Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/27/be/0631a861af4d1c875f096c07d34e9a63639560a717130e7a87cbc82b7e3f/python_json_logger-4.1.0-py3-none-any.whl", hash = "sha256:132994765cf75bf44554be9aa49b06ef2345d23661a96720262716438141b6b2", size = 15021, upload-time = "2026-03-29T04:39:55.266Z" },
+    { url = "https://files.pythonhosted.org/packages/dc/55/6467fde553886cb293e41538f3a8b4e4fd4688c6df242cf982162d8367fb/python_json_logger-4.2.0-py3-none-any.whl", hash = "sha256:158a52126fcd6869e09574d2b66272666f3dc8f468c62637ef9a1fa883719cb9", size = 14988, upload-time = "2026-08-15T11:36:36.821Z" },
 ]
 
 [[package]]