diff --git a/Directory.Packages.props b/Directory.Packages.props
index 084fea47dc..eb23af5e88 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -4,12 +4,13 @@
         <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
     </PropertyGroup>
     <ItemGroup>
-        <PackageVersion Include="FSharp.Core" Version="8.0.100"/>
+        <PackageVersion Include="FSharp.Core" Version="9.0.100"/>
         <PackageVersion Include="System.Collections.Immutable" Version="8.0.0" />
         <PackageVersion Include="System.Diagnostics.DiagnosticSource" Version="8.0.1" />
         <PackageVersion Include="System.Memory" Version="4.6.0" />
         <PackageVersion Include="System.Runtime" Version="4.3.1" />
         <PackageVersion Include="FsLexYacc" Version="11.3.0" />
+        <PackageVersion Include="FSharp.Core.Extended" Version="1.0.4" />
         
         <PackageVersion Include="Ionide.KeepAChangelog.Tasks" Version="0.1.8"/>
         <PackageVersion Include="DotNet.ReproducibleBuilds" Version="1.1.1"/>
diff --git a/global.json b/global.json
index 6f6aff9de6..5b8061cc75 100644
--- a/global.json
+++ b/global.json
@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "8.0.400",
+    "version": "9.0.100",
     "rollForward": "latestPatch"
   }
 }
\ No newline at end of file
diff --git a/src/Fantomas.Benchmarks/Fantomas.Benchmarks.fsproj b/src/Fantomas.Benchmarks/Fantomas.Benchmarks.fsproj
index 5152fe51d8..3f0fa2427c 100644
--- a/src/Fantomas.Benchmarks/Fantomas.Benchmarks.fsproj
+++ b/src/Fantomas.Benchmarks/Fantomas.Benchmarks.fsproj
@@ -2,7 +2,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
   <ItemGroup>
@@ -12,6 +12,7 @@
   <ItemGroup>
     <PackageReference Include="FSharp.Core" />
     <PackageReference Include="BenchmarkDotNet" />
+    <PackageReference Include="FSharp.Core.Extended" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Fantomas.Core\Fantomas.Core.fsproj" />
diff --git a/src/Fantomas.Benchmarks/packages.lock.json b/src/Fantomas.Benchmarks/packages.lock.json
index cc618a9806..d3c1f3e3b5 100644
--- a/src/Fantomas.Benchmarks/packages.lock.json
+++ b/src/Fantomas.Benchmarks/packages.lock.json
@@ -1,7 +1,7 @@
 {
   "version": 2,
   "dependencies": {
-    "net8.0": {
+    "net9.0": {
       "BenchmarkDotNet": {
         "type": "Direct",
         "requested": "[0.14.0, )",
@@ -28,9 +28,15 @@
       },
       "FSharp.Core": {
         "type": "Direct",
-        "requested": "[8.0.100, )",
-        "resolved": "8.0.100",
-        "contentHash": "ZOVZ/o+jI3ormTZOa28Wh0tSRoyle1f7lKFcUN61sPiXI7eDZu8eSveFybgTeyIEyW0ujjp31cp7GOglDgsNEg=="
+        "requested": "[9.0.100, )",
+        "resolved": "9.0.100",
+        "contentHash": "ye8yagHGsH08H2Twno5GRWkSbrMtxK/SWiHuPcF+3nODpW65/VJ8RO0aWxp8n9+KQbmahg90wAEL3TEXjF0r6A=="
+      },
+      "FSharp.Core.Extended": {
+        "type": "Direct",
+        "requested": "[1.0.4, )",
+        "resolved": "1.0.4",
+        "contentHash": "uwS+mTaOis2ZaFr6uPWhaFrDkluuXbZLU5CvX4tuA4HQhazHRjsAEuVV8wWEICQ2DEk9IwxIcC+WRwaEBPIVAQ=="
       },
       "G-Research.FSharp.Analyzers": {
         "type": "Direct",
@@ -272,14 +278,16 @@
       "fantomas.core": {
         "type": "Project",
         "dependencies": {
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
+          "FSharp.Core.Extended": "[1.0.4, )",
           "Fantomas.FCS": "[1.0.0, )"
         }
       },
       "fantomas.fcs": {
         "type": "Project",
         "dependencies": {
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
+          "FSharp.Core.Extended": "[1.0.4, )",
           "System.Collections.Immutable": "[8.0.0, )",
           "System.Diagnostics.DiagnosticSource": "[8.0.1, )",
           "System.Memory": "[4.6.0, )",
diff --git a/src/Fantomas.Client.Tests/packages.lock.json b/src/Fantomas.Client.Tests/packages.lock.json
index 6bbec117ff..2ebcfcf6b5 100644
--- a/src/Fantomas.Client.Tests/packages.lock.json
+++ b/src/Fantomas.Client.Tests/packages.lock.json
@@ -16,9 +16,9 @@
       },
       "FSharp.Core": {
         "type": "Direct",
-        "requested": "[8.0.100, )",
-        "resolved": "8.0.100",
-        "contentHash": "ZOVZ/o+jI3ormTZOa28Wh0tSRoyle1f7lKFcUN61sPiXI7eDZu8eSveFybgTeyIEyW0ujjp31cp7GOglDgsNEg=="
+        "requested": "[9.0.100, )",
+        "resolved": "9.0.100",
+        "contentHash": "ye8yagHGsH08H2Twno5GRWkSbrMtxK/SWiHuPcF+3nODpW65/VJ8RO0aWxp8n9+KQbmahg90wAEL3TEXjF0r6A=="
       },
       "G-Research.FSharp.Analyzers": {
         "type": "Direct",
@@ -137,7 +137,7 @@
       "fantomas.client": {
         "type": "Project",
         "dependencies": {
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
           "SemanticVersioning": "[2.0.2, )",
           "StreamJsonRpc": "[2.20.20, )"
         }
diff --git a/src/Fantomas.Client/packages.lock.json b/src/Fantomas.Client/packages.lock.json
index 65f0ab5696..adc5adf17a 100644
--- a/src/Fantomas.Client/packages.lock.json
+++ b/src/Fantomas.Client/packages.lock.json
@@ -22,9 +22,9 @@
       },
       "FSharp.Core": {
         "type": "Direct",
-        "requested": "[8.0.100, )",
-        "resolved": "8.0.100",
-        "contentHash": "ZOVZ/o+jI3ormTZOa28Wh0tSRoyle1f7lKFcUN61sPiXI7eDZu8eSveFybgTeyIEyW0ujjp31cp7GOglDgsNEg=="
+        "requested": "[9.0.100, )",
+        "resolved": "9.0.100",
+        "contentHash": "ye8yagHGsH08H2Twno5GRWkSbrMtxK/SWiHuPcF+3nODpW65/VJ8RO0aWxp8n9+KQbmahg90wAEL3TEXjF0r6A=="
       },
       "G-Research.FSharp.Analyzers": {
         "type": "Direct",
diff --git a/src/Fantomas.Core.Tests/Fantomas.Core.Tests.fsproj b/src/Fantomas.Core.Tests/Fantomas.Core.Tests.fsproj
index 6f606dc0ce..681f07f169 100644
--- a/src/Fantomas.Core.Tests/Fantomas.Core.Tests.fsproj
+++ b/src/Fantomas.Core.Tests/Fantomas.Core.Tests.fsproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <NoWarn>FS0988</NoWarn>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <WarningsAsErrors>FS0025</WarningsAsErrors>
     <IsPackable>false</IsPackable>
     <RollForward>Major</RollForward>
diff --git a/src/Fantomas.Core.Tests/packages.lock.json b/src/Fantomas.Core.Tests/packages.lock.json
index 50a2903a96..6d513e8ed6 100644
--- a/src/Fantomas.Core.Tests/packages.lock.json
+++ b/src/Fantomas.Core.Tests/packages.lock.json
@@ -1,7 +1,7 @@
 {
   "version": 2,
   "dependencies": {
-    "net8.0": {
+    "net9.0": {
       "FsCheck": {
         "type": "Direct",
         "requested": "[2.16.5, )",
@@ -19,9 +19,9 @@
       },
       "FSharp.Core": {
         "type": "Direct",
-        "requested": "[8.0.100, )",
-        "resolved": "8.0.100",
-        "contentHash": "ZOVZ/o+jI3ormTZOa28Wh0tSRoyle1f7lKFcUN61sPiXI7eDZu8eSveFybgTeyIEyW0ujjp31cp7GOglDgsNEg=="
+        "requested": "[9.0.100, )",
+        "resolved": "9.0.100",
+        "contentHash": "ye8yagHGsH08H2Twno5GRWkSbrMtxK/SWiHuPcF+3nODpW65/VJ8RO0aWxp8n9+KQbmahg90wAEL3TEXjF0r6A=="
       },
       "FsUnit": {
         "type": "Direct",
@@ -138,20 +138,28 @@
       "fantomas.core": {
         "type": "Project",
         "dependencies": {
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
+          "FSharp.Core.Extended": "[1.0.4, )",
           "Fantomas.FCS": "[1.0.0, )"
         }
       },
       "fantomas.fcs": {
         "type": "Project",
         "dependencies": {
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
+          "FSharp.Core.Extended": "[1.0.4, )",
           "System.Collections.Immutable": "[8.0.0, )",
           "System.Diagnostics.DiagnosticSource": "[8.0.1, )",
           "System.Memory": "[4.6.0, )",
           "System.Runtime": "[4.3.1, )"
         }
       },
+      "FSharp.Core.Extended": {
+        "type": "CentralTransitive",
+        "requested": "[1.0.4, )",
+        "resolved": "1.0.4",
+        "contentHash": "uwS+mTaOis2ZaFr6uPWhaFrDkluuXbZLU5CvX4tuA4HQhazHRjsAEuVV8wWEICQ2DEk9IwxIcC+WRwaEBPIVAQ=="
+      },
       "Newtonsoft.Json": {
         "type": "CentralTransitive",
         "requested": "[13.0.3, )",
diff --git a/src/Fantomas.Core/Fantomas.Core.fsproj b/src/Fantomas.Core/Fantomas.Core.fsproj
index 5ab93cf12a..ee9ab5dd33 100644
--- a/src/Fantomas.Core/Fantomas.Core.fsproj
+++ b/src/Fantomas.Core/Fantomas.Core.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <IsPackable>true</IsPackable>
     <Tailcalls>true</Tailcalls>
     <ProduceReferenceAssembly>true</ProduceReferenceAssembly>
@@ -40,6 +40,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="FSharp.Core" />
+    <PackageReference Include="FSharp.Core.Extended" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Fantomas.FCS\Fantomas.FCS.fsproj" />
diff --git a/src/Fantomas.Core/packages.lock.json b/src/Fantomas.Core/packages.lock.json
index 423ac63843..9ca40cf200 100644
--- a/src/Fantomas.Core/packages.lock.json
+++ b/src/Fantomas.Core/packages.lock.json
@@ -1,7 +1,7 @@
 {
   "version": 2,
   "dependencies": {
-    ".NETStandard,Version=v2.0": {
+    "net9.0": {
       "DotNet.ReproducibleBuilds": {
         "type": "Direct",
         "requested": "[1.1.1, )",
@@ -22,9 +22,15 @@
       },
       "FSharp.Core": {
         "type": "Direct",
-        "requested": "[8.0.100, )",
-        "resolved": "8.0.100",
-        "contentHash": "ZOVZ/o+jI3ormTZOa28Wh0tSRoyle1f7lKFcUN61sPiXI7eDZu8eSveFybgTeyIEyW0ujjp31cp7GOglDgsNEg=="
+        "requested": "[9.0.100, )",
+        "resolved": "9.0.100",
+        "contentHash": "ye8yagHGsH08H2Twno5GRWkSbrMtxK/SWiHuPcF+3nODpW65/VJ8RO0aWxp8n9+KQbmahg90wAEL3TEXjF0r6A=="
+      },
+      "FSharp.Core.Extended": {
+        "type": "Direct",
+        "requested": "[1.0.4, )",
+        "resolved": "1.0.4",
+        "contentHash": "uwS+mTaOis2ZaFr6uPWhaFrDkluuXbZLU5CvX4tuA4HQhazHRjsAEuVV8wWEICQ2DEk9IwxIcC+WRwaEBPIVAQ=="
       },
       "G-Research.FSharp.Analyzers": {
         "type": "Direct",
@@ -44,15 +50,6 @@
         "resolved": "0.1.8",
         "contentHash": "hHUZIVz9BlF++B5w183c5HwbqSIXUtJU+lxhKz3ebQ5X8INBIWV7dS/FK8uSqSMUTYavuKkRRTZvJlbYXPUykg=="
       },
-      "NETStandard.Library": {
-        "type": "Direct",
-        "requested": "[2.0.3, )",
-        "resolved": "2.0.3",
-        "contentHash": "st47PosZSHrjECdjeIzZQbzivYBJFv6P2nv4cj2ypdI204DO+vZ7l5raGMiX4eXMJ53RfOIg+/s4DHVZ54Nu2A==",
-        "dependencies": {
-          "Microsoft.NETCore.Platforms": "1.1.0"
-        }
-      },
       "Microsoft.Build.Tasks.Git": {
         "type": "Transitive",
         "resolved": "1.1.1",
@@ -109,25 +106,11 @@
           "Microsoft.SourceLink.Common": "1.1.1"
         }
       },
-      "System.Buffers": {
-        "type": "Transitive",
-        "resolved": "4.6.0",
-        "contentHash": "lN6tZi7Q46zFzAbRYXTIvfXcyvQQgxnY7Xm6C6xQ9784dEL1amjM6S6Iw4ZpsvesAKnRVsM4scrDQaDqSClkjA=="
-      },
-      "System.Numerics.Vectors": {
-        "type": "Transitive",
-        "resolved": "4.6.0",
-        "contentHash": "t+SoieZsRuEyiw/J+qXUbolyO219tKQQI0+2/YI+Qv7YdGValA6WiuokrNKqjrTNsy5ABWU11bdKOzUdheteXg=="
-      },
-      "System.Runtime.CompilerServices.Unsafe": {
-        "type": "Transitive",
-        "resolved": "6.1.0",
-        "contentHash": "5o/HZxx6RVqYlhKSq8/zronDkALJZUT2Vz0hx43f0gwe8mwlM0y2nYlqdBwLMzr262Bwvpikeb/yEwkAa5PADg=="
-      },
       "fantomas.fcs": {
         "type": "Project",
         "dependencies": {
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
+          "FSharp.Core.Extended": "[1.0.4, )",
           "System.Collections.Immutable": "[8.0.0, )",
           "System.Diagnostics.DiagnosticSource": "[8.0.1, )",
           "System.Memory": "[4.6.0, )",
@@ -138,32 +121,19 @@
         "type": "CentralTransitive",
         "requested": "[8.0.0, )",
         "resolved": "8.0.0",
-        "contentHash": "AurL6Y5BA1WotzlEvVaIDpqzpIPvYnnldxru8oXJU2yFxFUy3+pNXjXd1ymO+RA0rq0+590Q8gaz2l3Sr7fmqg==",
-        "dependencies": {
-          "System.Memory": "4.5.5",
-          "System.Runtime.CompilerServices.Unsafe": "6.0.0"
-        }
+        "contentHash": "AurL6Y5BA1WotzlEvVaIDpqzpIPvYnnldxru8oXJU2yFxFUy3+pNXjXd1ymO+RA0rq0+590Q8gaz2l3Sr7fmqg=="
       },
       "System.Diagnostics.DiagnosticSource": {
         "type": "CentralTransitive",
         "requested": "[8.0.1, )",
         "resolved": "8.0.1",
-        "contentHash": "vaoWjvkG1aenR2XdjaVivlCV9fADfgyhW5bZtXT23qaEea0lWiUljdQuze4E31vKM7ZWJaSUsbYIKE3rnzfZUg==",
-        "dependencies": {
-          "System.Memory": "4.5.5",
-          "System.Runtime.CompilerServices.Unsafe": "6.0.0"
-        }
+        "contentHash": "vaoWjvkG1aenR2XdjaVivlCV9fADfgyhW5bZtXT23qaEea0lWiUljdQuze4E31vKM7ZWJaSUsbYIKE3rnzfZUg=="
       },
       "System.Memory": {
         "type": "CentralTransitive",
         "requested": "[4.6.0, )",
         "resolved": "4.6.0",
-        "contentHash": "OEkbBQoklHngJ8UD8ez2AERSk2g+/qpAaSWWCBFbpH727HxDq5ydVkuncBaKcKfwRqXGWx64dS6G1SUScMsitg==",
-        "dependencies": {
-          "System.Buffers": "4.6.0",
-          "System.Numerics.Vectors": "4.6.0",
-          "System.Runtime.CompilerServices.Unsafe": "6.1.0"
-        }
+        "contentHash": "OEkbBQoklHngJ8UD8ez2AERSk2g+/qpAaSWWCBFbpH727HxDq5ydVkuncBaKcKfwRqXGWx64dS6G1SUScMsitg=="
       },
       "System.Runtime": {
         "type": "CentralTransitive",
diff --git a/src/Fantomas.FCS/Fantomas.FCS.fsproj b/src/Fantomas.FCS/Fantomas.FCS.fsproj
index dc2b8f3d4a..f8f7940a26 100644
--- a/src/Fantomas.FCS/Fantomas.FCS.fsproj
+++ b/src/Fantomas.FCS/Fantomas.FCS.fsproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <NoWarn>$(NoWarn);57;</NoWarn> <!-- Experimental -->
     <NoWarn>$(NoWarn);1204</NoWarn> <!-- This construct is for use in the FSharp.Core library and should not be used directly -->
@@ -325,6 +325,7 @@
     <PackageReference Include="System.Memory" />
     <PackageReference Include="System.Runtime" />
     <PackageReference Include="FsLexYacc" PrivateAssets="all" />
+    <PackageReference Include="FSharp.Core.Extended" />
   </ItemGroup>
 
   <Target Name="AcquireCompilerFiles" Condition="!Exists('../../.deps/$(FCSCommitHash)')" BeforeTargets="CollectPackageReferences">
diff --git a/src/Fantomas.FCS/packages.lock.json b/src/Fantomas.FCS/packages.lock.json
index 9482e407e7..47a6ed0b8d 100644
--- a/src/Fantomas.FCS/packages.lock.json
+++ b/src/Fantomas.FCS/packages.lock.json
@@ -1,7 +1,7 @@
 {
   "version": 2,
   "dependencies": {
-    ".NETStandard,Version=v2.0": {
+    "net9.0": {
       "DotNet.ReproducibleBuilds": {
         "type": "Direct",
         "requested": "[1.1.1, )",
@@ -22,9 +22,15 @@
       },
       "FSharp.Core": {
         "type": "Direct",
-        "requested": "[8.0.100, )",
-        "resolved": "8.0.100",
-        "contentHash": "ZOVZ/o+jI3ormTZOa28Wh0tSRoyle1f7lKFcUN61sPiXI7eDZu8eSveFybgTeyIEyW0ujjp31cp7GOglDgsNEg=="
+        "requested": "[9.0.100, )",
+        "resolved": "9.0.100",
+        "contentHash": "ye8yagHGsH08H2Twno5GRWkSbrMtxK/SWiHuPcF+3nODpW65/VJ8RO0aWxp8n9+KQbmahg90wAEL3TEXjF0r6A=="
+      },
+      "FSharp.Core.Extended": {
+        "type": "Direct",
+        "requested": "[1.0.4, )",
+        "resolved": "1.0.4",
+        "contentHash": "uwS+mTaOis2ZaFr6uPWhaFrDkluuXbZLU5CvX4tuA4HQhazHRjsAEuVV8wWEICQ2DEk9IwxIcC+WRwaEBPIVAQ=="
       },
       "FsLexYacc": {
         "type": "Direct",
@@ -54,45 +60,23 @@
         "resolved": "0.1.8",
         "contentHash": "hHUZIVz9BlF++B5w183c5HwbqSIXUtJU+lxhKz3ebQ5X8INBIWV7dS/FK8uSqSMUTYavuKkRRTZvJlbYXPUykg=="
       },
-      "NETStandard.Library": {
-        "type": "Direct",
-        "requested": "[2.0.3, )",
-        "resolved": "2.0.3",
-        "contentHash": "st47PosZSHrjECdjeIzZQbzivYBJFv6P2nv4cj2ypdI204DO+vZ7l5raGMiX4eXMJ53RfOIg+/s4DHVZ54Nu2A==",
-        "dependencies": {
-          "Microsoft.NETCore.Platforms": "1.1.0"
-        }
-      },
       "System.Collections.Immutable": {
         "type": "Direct",
         "requested": "[8.0.0, )",
         "resolved": "8.0.0",
-        "contentHash": "AurL6Y5BA1WotzlEvVaIDpqzpIPvYnnldxru8oXJU2yFxFUy3+pNXjXd1ymO+RA0rq0+590Q8gaz2l3Sr7fmqg==",
-        "dependencies": {
-          "System.Memory": "4.5.5",
-          "System.Runtime.CompilerServices.Unsafe": "6.0.0"
-        }
+        "contentHash": "AurL6Y5BA1WotzlEvVaIDpqzpIPvYnnldxru8oXJU2yFxFUy3+pNXjXd1ymO+RA0rq0+590Q8gaz2l3Sr7fmqg=="
       },
       "System.Diagnostics.DiagnosticSource": {
         "type": "Direct",
         "requested": "[8.0.1, )",
         "resolved": "8.0.1",
-        "contentHash": "vaoWjvkG1aenR2XdjaVivlCV9fADfgyhW5bZtXT23qaEea0lWiUljdQuze4E31vKM7ZWJaSUsbYIKE3rnzfZUg==",
-        "dependencies": {
-          "System.Memory": "4.5.5",
-          "System.Runtime.CompilerServices.Unsafe": "6.0.0"
-        }
+        "contentHash": "vaoWjvkG1aenR2XdjaVivlCV9fADfgyhW5bZtXT23qaEea0lWiUljdQuze4E31vKM7ZWJaSUsbYIKE3rnzfZUg=="
       },
       "System.Memory": {
         "type": "Direct",
         "requested": "[4.6.0, )",
         "resolved": "4.6.0",
-        "contentHash": "OEkbBQoklHngJ8UD8ez2AERSk2g+/qpAaSWWCBFbpH727HxDq5ydVkuncBaKcKfwRqXGWx64dS6G1SUScMsitg==",
-        "dependencies": {
-          "System.Buffers": "4.6.0",
-          "System.Numerics.Vectors": "4.6.0",
-          "System.Runtime.CompilerServices.Unsafe": "6.1.0"
-        }
+        "contentHash": "OEkbBQoklHngJ8UD8ez2AERSk2g+/qpAaSWWCBFbpH727HxDq5ydVkuncBaKcKfwRqXGWx64dS6G1SUScMsitg=="
       },
       "System.Runtime": {
         "type": "Direct",
@@ -167,21 +151,6 @@
           "Microsoft.Build.Tasks.Git": "1.1.1",
           "Microsoft.SourceLink.Common": "1.1.1"
         }
-      },
-      "System.Buffers": {
-        "type": "Transitive",
-        "resolved": "4.6.0",
-        "contentHash": "lN6tZi7Q46zFzAbRYXTIvfXcyvQQgxnY7Xm6C6xQ9784dEL1amjM6S6Iw4ZpsvesAKnRVsM4scrDQaDqSClkjA=="
-      },
-      "System.Numerics.Vectors": {
-        "type": "Transitive",
-        "resolved": "4.6.0",
-        "contentHash": "t+SoieZsRuEyiw/J+qXUbolyO219tKQQI0+2/YI+Qv7YdGValA6WiuokrNKqjrTNsy5ABWU11bdKOzUdheteXg=="
-      },
-      "System.Runtime.CompilerServices.Unsafe": {
-        "type": "Transitive",
-        "resolved": "6.1.0",
-        "contentHash": "5o/HZxx6RVqYlhKSq8/zronDkALJZUT2Vz0hx43f0gwe8mwlM0y2nYlqdBwLMzr262Bwvpikeb/yEwkAa5PADg=="
       }
     }
   }
diff --git a/src/Fantomas.Tests/Fantomas.Tests.fsproj b/src/Fantomas.Tests/Fantomas.Tests.fsproj
index 8243c389c8..8e265d215d 100644
--- a/src/Fantomas.Tests/Fantomas.Tests.fsproj
+++ b/src/Fantomas.Tests/Fantomas.Tests.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <IsPackable>false</IsPackable>
     <GenerateProgramFile>false</GenerateProgramFile>
     <NoWarn>FS0988</NoWarn>
diff --git a/src/Fantomas.Tests/packages.lock.json b/src/Fantomas.Tests/packages.lock.json
index 7c8f686ebd..78305b7540 100644
--- a/src/Fantomas.Tests/packages.lock.json
+++ b/src/Fantomas.Tests/packages.lock.json
@@ -1,7 +1,7 @@
 {
   "version": 2,
   "dependencies": {
-    "net8.0": {
+    "net9.0": {
       "FsCheck": {
         "type": "Direct",
         "requested": "[2.16.5, )",
@@ -19,9 +19,9 @@
       },
       "FSharp.Core": {
         "type": "Direct",
-        "requested": "[8.0.100, )",
-        "resolved": "8.0.100",
-        "contentHash": "ZOVZ/o+jI3ormTZOa28Wh0tSRoyle1f7lKFcUN61sPiXI7eDZu8eSveFybgTeyIEyW0ujjp31cp7GOglDgsNEg=="
+        "requested": "[9.0.100, )",
+        "resolved": "9.0.100",
+        "contentHash": "ye8yagHGsH08H2Twno5GRWkSbrMtxK/SWiHuPcF+3nODpW65/VJ8RO0aWxp8n9+KQbmahg90wAEL3TEXjF0r6A=="
       },
       "FsUnit": {
         "type": "Direct",
@@ -213,7 +213,7 @@
         "type": "Project",
         "dependencies": {
           "Argu": "[6.2.4, )",
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
           "Fantomas.Client": "[1.0.0, )",
           "Fantomas.Core": "[1.0.0, )",
           "Ignore": "[0.2.1, )",
@@ -230,7 +230,7 @@
       "fantomas.client": {
         "type": "Project",
         "dependencies": {
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
           "SemanticVersioning": "[2.0.2, )",
           "StreamJsonRpc": "[2.20.20, )"
         }
@@ -238,14 +238,16 @@
       "fantomas.core": {
         "type": "Project",
         "dependencies": {
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
+          "FSharp.Core.Extended": "[1.0.4, )",
           "Fantomas.FCS": "[1.0.0, )"
         }
       },
       "fantomas.fcs": {
         "type": "Project",
         "dependencies": {
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
+          "FSharp.Core.Extended": "[1.0.4, )",
           "System.Collections.Immutable": "[8.0.0, )",
           "System.Diagnostics.DiagnosticSource": "[8.0.1, )",
           "System.Memory": "[4.6.0, )",
@@ -268,6 +270,12 @@
         "resolved": "0.15.0",
         "contentHash": "NuUxFbycSCOhl0WzmNZ8ksSMrTHBFzTASkil+IOqXpqTXszokKjy6ihxMdjArGaC+AaLLq4nxfGVFLi6KWyFJg=="
       },
+      "FSharp.Core.Extended": {
+        "type": "CentralTransitive",
+        "requested": "[1.0.4, )",
+        "resolved": "1.0.4",
+        "contentHash": "uwS+mTaOis2ZaFr6uPWhaFrDkluuXbZLU5CvX4tuA4HQhazHRjsAEuVV8wWEICQ2DEk9IwxIcC+WRwaEBPIVAQ=="
+      },
       "Ignore": {
         "type": "CentralTransitive",
         "requested": "[0.2.1, )",
diff --git a/src/Fantomas/Fantomas.fsproj b/src/Fantomas/Fantomas.fsproj
index 08a87ac2bd..d94d4b840b 100644
--- a/src/Fantomas/Fantomas.fsproj
+++ b/src/Fantomas/Fantomas.fsproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <!-- Don't create localization (en-US, etc) folders with resources -->
     <!-- https://github.com/dotnet/fsharp/issues/6007#issuecomment-547041463 -->
     <SatelliteResourceLanguages>en</SatelliteResourceLanguages>
diff --git a/src/Fantomas/packages.lock.json b/src/Fantomas/packages.lock.json
index a69893af5b..f9c2c36b85 100644
--- a/src/Fantomas/packages.lock.json
+++ b/src/Fantomas/packages.lock.json
@@ -1,7 +1,7 @@
 {
   "version": 2,
   "dependencies": {
-    "net8.0": {
+    "net9.0": {
       "Argu": {
         "type": "Direct",
         "requested": "[6.2.4, )",
@@ -38,9 +38,9 @@
       },
       "FSharp.Core": {
         "type": "Direct",
-        "requested": "[8.0.100, )",
-        "resolved": "8.0.100",
-        "contentHash": "ZOVZ/o+jI3ormTZOa28Wh0tSRoyle1f7lKFcUN61sPiXI7eDZu8eSveFybgTeyIEyW0ujjp31cp7GOglDgsNEg=="
+        "requested": "[9.0.100, )",
+        "resolved": "9.0.100",
+        "contentHash": "ye8yagHGsH08H2Twno5GRWkSbrMtxK/SWiHuPcF+3nODpW65/VJ8RO0aWxp8n9+KQbmahg90wAEL3TEXjF0r6A=="
       },
       "G-Research.FSharp.Analyzers": {
         "type": "Direct",
@@ -278,7 +278,7 @@
       "fantomas.client": {
         "type": "Project",
         "dependencies": {
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
           "SemanticVersioning": "[2.0.2, )",
           "StreamJsonRpc": "[2.20.20, )"
         }
@@ -286,20 +286,28 @@
       "fantomas.core": {
         "type": "Project",
         "dependencies": {
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
+          "FSharp.Core.Extended": "[1.0.4, )",
           "Fantomas.FCS": "[1.0.0, )"
         }
       },
       "fantomas.fcs": {
         "type": "Project",
         "dependencies": {
-          "FSharp.Core": "[8.0.100, )",
+          "FSharp.Core": "[9.0.100, )",
+          "FSharp.Core.Extended": "[1.0.4, )",
           "System.Collections.Immutable": "[8.0.0, )",
           "System.Diagnostics.DiagnosticSource": "[8.0.1, )",
           "System.Memory": "[4.6.0, )",
           "System.Runtime": "[4.3.1, )"
         }
       },
+      "FSharp.Core.Extended": {
+        "type": "CentralTransitive",
+        "requested": "[1.0.4, )",
+        "resolved": "1.0.4",
+        "contentHash": "uwS+mTaOis2ZaFr6uPWhaFrDkluuXbZLU5CvX4tuA4HQhazHRjsAEuVV8wWEICQ2DEk9IwxIcC+WRwaEBPIVAQ=="
+      },
       "Newtonsoft.Json": {
         "type": "CentralTransitive",
         "requested": "[13.0.3, )",