diff --git a/src/AzureMutex.Tests/packages.lock.json b/src/AzureMutex.Tests/packages.lock.json
index ee65490..a00926d 100644
--- a/src/AzureMutex.Tests/packages.lock.json
+++ b/src/AzureMutex.Tests/packages.lock.json
@@ -24,9 +24,9 @@
       },
       "NUnit": {
         "type": "Direct",
-        "requested": "[4.2.2, )",
-        "resolved": "4.2.2",
-        "contentHash": "mon0OPko28yZ/foVXrhiUvq1LReaGsBdziumyyYGxV/pOE4q92fuYeN+AF+gEU5pCjzykcdBt5l7xobTaiBjsg=="
+        "requested": "[4.3.1, )",
+        "resolved": "4.3.1",
+        "contentHash": "798HDjDWfo2/BVWAeqIny3hRP2z/uk2EVeTeFB69EGHQWxFZ1oVXRaobtOdkzBF4b/olUuWXDJzgtW63aBRDxg=="
       },
       "NUnit3TestAdapter": {
         "type": "Direct",
diff --git a/src/Directory.Packages.props b/src/Directory.Packages.props
index 287dd41..a67d088 100644
--- a/src/Directory.Packages.props
+++ b/src/Directory.Packages.props
@@ -8,7 +8,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
-    <PackageVersion Include="NUnit" Version="4.2.2" />
+    <PackageVersion Include="NUnit" Version="4.3.1" />
     <PackageVersion Include="NUnit3TestAdapter" Version="4.6.0" />
   </ItemGroup>
 </Project>