diff --git a/Directory.Packages.props b/Directory.Packages.props
index 1ba3a3f..5ead3a2 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -6,8 +6,8 @@
 
   <ItemGroup>
     <PackageVersion Include="DocumentFormat.OpenXml" Version="3.5.1" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.8.1" />
     <PackageVersion Include="xunit" Version="2.9.3" />
-    <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.2" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
   </ItemGroup>
 </Project>
diff --git a/tests/CellSharp.Tests/packages.lock.json b/tests/CellSharp.Tests/packages.lock.json
index b37b1e3..0830063 100644
--- a/tests/CellSharp.Tests/packages.lock.json
+++ b/tests/CellSharp.Tests/packages.lock.json
@@ -13,12 +13,12 @@
       },
       "Microsoft.NET.Test.Sdk": {
         "type": "Direct",
-        "requested": "[17.12.0, )",
-        "resolved": "17.12.0",
-        "contentHash": "kt/PKBZ91rFCWxVIJZSgVLk+YR+4KxTuHf799ho8WNiK5ZQpJNAEZCAWX86vcKrs+DiYjiibpYKdGZP6+/N17w==",
+        "requested": "[18.8.1, )",
+        "resolved": "18.8.1",
+        "contentHash": "dknJL3/9Y3t4XuCBqnc0PevPxgLsUMmVhjwup/b1HNovA8zWcj3XsfIf7c6p05363DWcqL7X/YhDL9B+Zymv1w==",
         "dependencies": {
-          "Microsoft.CodeCoverage": "17.12.0",
-          "Microsoft.TestPlatform.TestHost": "17.12.0"
+          "Microsoft.CodeCoverage": "18.8.1",
+          "Microsoft.TestPlatform.TestHost": "18.8.1"
         }
       },
       "xunit": {
@@ -34,9 +34,9 @@
       },
       "xunit.runner.visualstudio": {
         "type": "Direct",
-        "requested": "[2.8.2, )",
-        "resolved": "2.8.2",
-        "contentHash": "vm1tbfXhFmjFMUmS4M0J0ASXz3/U5XvXBa6DOQUL3fEz4Vt6YPhv+ESCarx6M6D+9kJkJYZKCNvJMas1+nVfmQ=="
+        "requested": "[3.1.5, )",
+        "resolved": "3.1.5",
+        "contentHash": "tKi7dSTwP4m5m9eXPM2Ime4Kn7xNf4x4zT9sdLO/G4hZVnQCRiMTWoSZqI/pYTVeI27oPPqHBKYI/DjJ9GsYgA=="
       },
       "DocumentFormat.OpenXml.Framework": {
         "type": "Transitive",
@@ -48,30 +48,29 @@
       },
       "Microsoft.CodeCoverage": {
         "type": "Transitive",
-        "resolved": "17.12.0",
-        "contentHash": "4svMznBd5JM21JIG2xZKGNanAHNXplxf/kQDFfLHXQ3OnpJkayRK/TjacFjA+EYmoyuNXHo/sOETEfcYtAzIrA=="
+        "resolved": "18.8.1",
+        "contentHash": "Eclse/ZZjr4lmWzZFNN9h/OluhKL+SK/QbUyKUewgX139aGeyMEO/DkMPwuFs2MixvanTnz6891rF8UHDg+W4Q=="
       },
       "Microsoft.TestPlatform.ObjectModel": {
         "type": "Transitive",
-        "resolved": "17.12.0",
-        "contentHash": "TDqkTKLfQuAaPcEb3pDDWnh7b3SyZF+/W9OZvWFp6eJCIiiYFdSB6taE2I6tWrFw5ywhzOb6sreoGJTI6m3rSQ==",
+        "resolved": "18.8.1",
+        "contentHash": "qLbktNB1+b1XZLNJBTzaWVVJAd6PEzD7cgD406geMb6PcFZhp3EDNa1tctWx1+mtMU6MP/6ozVvFPC9vs2a9rw==",
         "dependencies": {
-          "System.Reflection.Metadata": "1.6.0"
+          "System.Reflection.Metadata": "8.0.0"
         }
       },
       "Microsoft.TestPlatform.TestHost": {
         "type": "Transitive",
-        "resolved": "17.12.0",
-        "contentHash": "MiPEJQNyADfwZ4pJNpQex+t9/jOClBGMiCiVVFuELCMSX2nmNfvUor3uFVxNNCg30uxDP8JDYfPnMXQzsfzYyg==",
+        "resolved": "18.8.1",
+        "contentHash": "FaQHPDTUOcE+SFTjssNPfrub2lT9Zyon4J2W/KLHt/efLJACb1TCeWXyOgh0D/4Q1e4n+S3E6mOKud+9nLZlEA==",
         "dependencies": {
-          "Microsoft.TestPlatform.ObjectModel": "17.12.0",
-          "Newtonsoft.Json": "13.0.1"
+          "Microsoft.TestPlatform.ObjectModel": "18.8.1"
         }
       },
-      "Newtonsoft.Json": {
+      "System.Collections.Immutable": {
         "type": "Transitive",
-        "resolved": "13.0.1",
-        "contentHash": "ppPFpBcvxdsfUonNcvITKqLl3bqxWbDCZIzDWHzjpdAHRFfZe0Dw9HmA0+za13IdyrgJwpkDTDA9fHaxOrt20A=="
+        "resolved": "8.0.0",
+        "contentHash": "AurL6Y5BA1WotzlEvVaIDpqzpIPvYnnldxru8oXJU2yFxFUy3+pNXjXd1ymO+RA0rq0+590Q8gaz2l3Sr7fmqg=="
       },
       "System.IO.Packaging": {
         "type": "Transitive",
@@ -80,8 +79,11 @@
       },
       "System.Reflection.Metadata": {
         "type": "Transitive",
-        "resolved": "1.6.0",
-        "contentHash": "COC1aiAJjCoA5GBF+QKL2uLqEBew4JsCkQmoHKbN3TlOZKa2fKLz5CpiRQKDz0RsAOEGsVKqOD5bomsXq/4STQ=="
+        "resolved": "8.0.0",
+        "contentHash": "ptvgrFh7PvWI8bcVqG5rsA/weWM09EnthFHR5SCnS6IN+P4mj6rE1lBDC4U8HL9/57htKAqy4KQ3bBj84cfYyQ==",
+        "dependencies": {
+          "System.Collections.Immutable": "8.0.0"
+        }
       },
       "xunit.abstractions": {
         "type": "Transitive",