diff --git a/docs/apidocs.fsx b/docs/apidocs.fsx
index c2ea469d4..0178ff7f0 100644
--- a/docs/apidocs.fsx
+++ b/docs/apidocs.fsx
@@ -8,7 +8,7 @@ index: 6
 *)
 (*** condition: prepare ***)
 #nowarn "211"
-#I "../src/FSharp.Formatting/bin/Release/netstandard2.1"
+#I "../src/FSharp.Formatting/bin/Release/netstandard2.0"
 #r "FSharp.Compiler.Service"
 #r "FSharp.Formatting.Common.dll"
 #r "FSharp.Formatting.Markdown.dll"
diff --git a/docs/codeformat.fsx b/docs/codeformat.fsx
index 3c36b4dfb..4da131b88 100644
--- a/docs/codeformat.fsx
+++ b/docs/codeformat.fsx
@@ -7,7 +7,7 @@ index: 1
 *)
 (*** condition: prepare ***)
 #nowarn "211"
-#I "../src/FSharp.Formatting/bin/Release/netstandard2.1"
+#I "../src/FSharp.Formatting/bin/Release/netstandard2.0"
 #r "FSharp.Formatting.Common.dll"
 #r "FSharp.Formatting.Markdown.dll"
 #r "FSharp.Formatting.CodeFormat.dll"
diff --git a/docs/content.fsx b/docs/content.fsx
index b686c6566..d6b0e0ced 100644
--- a/docs/content.fsx
+++ b/docs/content.fsx
@@ -7,7 +7,7 @@ index: 5
 *)
 (*** condition: prepare ***)
 #nowarn "211"
-#I "../src/FSharp.Formatting/bin/Release/netstandard2.1"
+#I "../src/FSharp.Formatting/bin/Release/netstandard2.0"
 #r "FSharp.Formatting.Common.dll"
 #r "FSharp.Formatting.Markdown.dll"
 #r "FSharp.Formatting.CodeFormat.dll"
diff --git a/docs/evaluation.fsx b/docs/evaluation.fsx
index 1fe4fbb5d..0acb62f42 100644
--- a/docs/evaluation.fsx
+++ b/docs/evaluation.fsx
@@ -7,7 +7,7 @@ index: 7
 *)
 (*** condition: prepare ***)
 #nowarn "211"
-#I "../src/FSharp.Formatting/bin/Release/netstandard2.1"
+#I "../src/FSharp.Formatting/bin/Release/netstandard2.0"
 #r "FSharp.Formatting.Common.dll"
 #r "FSharp.Formatting.Markdown.dll"
 #r "FSharp.Formatting.CodeFormat.dll"
diff --git a/docs/literate.fsx b/docs/literate.fsx
index ecbd7475e..be23c0d37 100644
--- a/docs/literate.fsx
+++ b/docs/literate.fsx
@@ -7,7 +7,7 @@ index: 3
 *)
 (*** condition: prepare ***)
 #nowarn "211"
-#I "../src/FSharp.Formatting/bin/Release/netstandard2.1"
+#I "../src/FSharp.Formatting/bin/Release/netstandard2.0"
 #r "FSharp.Formatting.Common.dll"
 #r "FSharp.Formatting.Markdown.dll"
 #r "FSharp.Formatting.CodeFormat.dll"
@@ -197,7 +197,7 @@ A header may be needed to get the code to load, a typical example is this:
 ```text
     (*** condition: prepare ***)
     #nowarn "211"
-    #I "../src/FSharp.Formatting/bin/Release/netstandard2.1"
+    #I "../src/FSharp.Formatting/bin/Release/netstandard2.0"
     #r "FSharp.Formatting.Common.dll"
     #r "FSharp.Formatting.Markdown.dll"
     #r "FSharp.Formatting.CodeFormat.dll"
diff --git a/docs/markdown.fsx b/docs/markdown.fsx
index 58dc54c36..0719e950a 100644
--- a/docs/markdown.fsx
+++ b/docs/markdown.fsx
@@ -6,7 +6,7 @@ index: 2
 ---
 *)
 (*** condition: prepare ***)
-#I "../src/FSharp.Formatting/bin/Release/netstandard2.1"
+#I "../src/FSharp.Formatting/bin/Release/netstandard2.0"
 #r "FSharp.Formatting.Common.dll"
 #r "FSharp.Formatting.Markdown.dll"
 (*** condition: fsx ***)
diff --git a/src/FSharp.Formatting.ApiDocs/FSharp.Formatting.ApiDocs.fsproj b/src/FSharp.Formatting.ApiDocs/FSharp.Formatting.ApiDocs.fsproj
index 1255480ce..1ff69c10f 100644
--- a/src/FSharp.Formatting.ApiDocs/FSharp.Formatting.ApiDocs.fsproj
+++ b/src/FSharp.Formatting.ApiDocs/FSharp.Formatting.ApiDocs.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="..\Common\Collections.fs">
diff --git a/src/FSharp.Formatting.ApiDocs/GenerateHtml.fs b/src/FSharp.Formatting.ApiDocs/GenerateHtml.fs
index f6176fb68..ddb6ab7f4 100644
--- a/src/FSharp.Formatting.ApiDocs/GenerateHtml.fs
+++ b/src/FSharp.Formatting.ApiDocs/GenerateHtml.fs
@@ -5,6 +5,10 @@ open System.Collections.Generic
 open System.IO
 open System.Web
 open FSharp.Formatting.Common
+#if NETSTANDARD2_1_OR_GREATER
+#else
+open FSharp.Formatting.Common.Utils // compat layer for netstandard2.0
+#endif
 open FSharp.Compiler.Symbols
 open FSharp.Formatting.Templating
 open FSharp.Formatting.HtmlModel
diff --git a/src/FSharp.Formatting.ApiDocs/GenerateModel.fs b/src/FSharp.Formatting.ApiDocs/GenerateModel.fs
index 5a8eaa593..5c5586512 100644
--- a/src/FSharp.Formatting.ApiDocs/GenerateModel.fs
+++ b/src/FSharp.Formatting.ApiDocs/GenerateModel.fs
@@ -13,6 +13,10 @@ open FSharp.Compiler.Symbols
 open FSharp.Compiler.Text
 open FSharp.Compiler.Text.Range
 open FSharp.Formatting.Common
+#if NETSTANDARD2_1_OR_GREATER
+#else
+open FSharp.Formatting.Common.Utils // compat layer for netstandard2.0
+#endif
 open FSharp.Formatting.Internal
 open FSharp.Formatting.CodeFormat
 open FSharp.Formatting.Literate
diff --git a/src/FSharp.Formatting.CSharpFormat/FSharp.Formatting.CSharpFormat.csproj b/src/FSharp.Formatting.CSharpFormat/FSharp.Formatting.CSharpFormat.csproj
index c16de1446..738cfe10b 100644
--- a/src/FSharp.Formatting.CSharpFormat/FSharp.Formatting.CSharpFormat.csproj
+++ b/src/FSharp.Formatting.CSharpFormat/FSharp.Formatting.CSharpFormat.csproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Folder Include="Properties\" />
diff --git a/src/FSharp.Formatting.CodeFormat/FSharp.Formatting.CodeFormat.fsproj b/src/FSharp.Formatting.CodeFormat/FSharp.Formatting.CodeFormat.fsproj
index b6a901eea..b0dc71e91 100644
--- a/src/FSharp.Formatting.CodeFormat/FSharp.Formatting.CodeFormat.fsproj
+++ b/src/FSharp.Formatting.CodeFormat/FSharp.Formatting.CodeFormat.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="..\Common\Collections.fs">
diff --git a/src/FSharp.Formatting.Common/FSharp.Formatting.Common.fsproj b/src/FSharp.Formatting.Common/FSharp.Formatting.Common.fsproj
index d0756aaed..92db79ba7 100644
--- a/src/FSharp.Formatting.Common/FSharp.Formatting.Common.fsproj
+++ b/src/FSharp.Formatting.Common/FSharp.Formatting.Common.fsproj
@@ -1,12 +1,13 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <DefineConstants>TRACE;YAAF_FSHARP_SCRIPTING_PUBLIC</DefineConstants>
     <DisableMSBuildAssemblyCopyCheck>true</DisableMSBuildAssemblyCopyCheck>
     <WarningsAsErrors>FS0025;FS1182;$(WarningsAsErrors)</WarningsAsErrors>
   </PropertyGroup>
   <ItemGroup>
+    <Compile Include="Utils.fs" />
     <Compile Include="YaafFSharpScripting.fs" />
     <Compile Include="Log.fs" />
     <Compile Include="Range.fs" />
diff --git a/src/FSharp.Formatting.Common/PynbModel.fs b/src/FSharp.Formatting.Common/PynbModel.fs
index 3afd8cefb..2f7137882 100644
--- a/src/FSharp.Formatting.Common/PynbModel.fs
+++ b/src/FSharp.Formatting.Common/PynbModel.fs
@@ -1,5 +1,9 @@
 module internal FSharp.Formatting.PynbModel
 
+#if NETSTANDARD2_1_OR_GREATER
+#else
+open FSharp.Formatting.Common.Utils // compat layer for netstandard2.0
+#endif
 open System.Web
 
 let escapeAndQuote (txt: string) =
diff --git a/src/FSharp.Formatting.Common/Templating.fs b/src/FSharp.Formatting.Common/Templating.fs
index 2656c7b40..803214a8a 100644
--- a/src/FSharp.Formatting.Common/Templating.fs
+++ b/src/FSharp.Formatting.Common/Templating.fs
@@ -4,6 +4,7 @@ open System
 open System.Collections.Generic
 open System.IO
 open System.Text
+open FSharp.Formatting.Common.Utils // compat layer for netstandard2.0
 
 /// <summary>
 /// A parameter key
@@ -50,7 +51,7 @@ type FrontMatterFile =
                 isBlankLine || line.Contains(":"))
             |> Seq.filter (String.IsNullOrWhiteSpace >> not)
             |> Seq.map (fun line ->
-                let parts = line.Split(":")
+                let parts = line.Split ':'
                 parts.[0].ToLowerInvariant(), parts.[1])
             |> Map.ofSeq
 
diff --git a/src/FSharp.Formatting.Common/Utils.fs b/src/FSharp.Formatting.Common/Utils.fs
new file mode 100644
index 000000000..f467ecdac
--- /dev/null
+++ b/src/FSharp.Formatting.Common/Utils.fs
@@ -0,0 +1,13 @@
+module FSharp.Formatting.Common.Utils
+#if NETSTANDARD_2_1_OR_GREATER
+#else
+open System
+
+type String with
+    member x.StartsWith c = x.StartsWith(string<char> c, StringComparison.Ordinal)
+
+    member x.EndsWith c =
+        x.EndsWith(string<char> c, StringComparison.Ordinal)
+
+    member x.Contains c = x.Contains(string<char> c)
+#endif
diff --git a/src/FSharp.Formatting.Literate/FSharp.Formatting.Literate.fsproj b/src/FSharp.Formatting.Literate/FSharp.Formatting.Literate.fsproj
index 25e193476..b6fa230ac 100644
--- a/src/FSharp.Formatting.Literate/FSharp.Formatting.Literate.fsproj
+++ b/src/FSharp.Formatting.Literate/FSharp.Formatting.Literate.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
     <IsPackable>true</IsPackable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/src/FSharp.Formatting.Literate/Formatting.fs b/src/FSharp.Formatting.Literate/Formatting.fs
index bb7083467..a9cb9413c 100644
--- a/src/FSharp.Formatting.Literate/Formatting.fs
+++ b/src/FSharp.Formatting.Literate/Formatting.fs
@@ -150,8 +150,22 @@ module internal Formatting =
             let relativeSourceFileName =
                 match doc.RootInputFolder with
                 | None -> Path.GetFileName(doc.SourceFile)
-                | Some rootInputFolder -> Path.GetRelativePath(rootInputFolder, doc.SourceFile)
-
+                | Some rootInputFolder ->
+#if NETSTANDARD2_1_OR_GREATER
+                    Path.GetRelativePath(rootInputFolder, doc.SourceFile)
+#else
+                    if
+                        doc.SourceFile.StartsWith(
+                            rootInputFolder + string<char> Path.DirectorySeparatorChar,
+                            StringComparison.Ordinal
+                        )
+                        || doc.SourceFile.StartsWith(rootInputFolder + "/", StringComparison.Ordinal)
+                        || doc.SourceFile.StartsWith(rootInputFolder + "\\", StringComparison.Ordinal)
+                    then
+                        doc.SourceFile.Substring(rootInputFolder.Length + 1)
+                    else
+                        failwith $"need to make {doc.SourceFile} relative to {rootInputFolder}"
+#endif
             let relativeSourceFileBaseName = Path.ChangeExtension(relativeSourceFileName, null)
 
             let relativeSourceFileName = relativeSourceFileName.Replace(@"\", "/")
diff --git a/src/FSharp.Formatting.Markdown/FSharp.Formatting.Markdown.fsproj b/src/FSharp.Formatting.Markdown/FSharp.Formatting.Markdown.fsproj
index 2a91fe9b9..e6e9ace85 100644
--- a/src/FSharp.Formatting.Markdown/FSharp.Formatting.Markdown.fsproj
+++ b/src/FSharp.Formatting.Markdown/FSharp.Formatting.Markdown.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="..\Common\Collections.fs">
diff --git a/src/FSharp.Formatting.Markdown/MarkdownParser.fs b/src/FSharp.Formatting.Markdown/MarkdownParser.fs
index 739e95674..ed9614b35 100644
--- a/src/FSharp.Formatting.Markdown/MarkdownParser.fs
+++ b/src/FSharp.Formatting.Markdown/MarkdownParser.fs
@@ -12,7 +12,10 @@ open System.Text.RegularExpressions
 open FSharp.Patterns
 open FSharp.Collections
 open FSharp.Formatting.Common
-
+#if NETSTANDARD2_1_OR_GREATER
+#else
+open FSharp.Formatting.Common.Utils // compat layer for netstandard2.0
+#endif
 // --------------------------------------------------------------------------------------
 // Parsing of Markdown - first part handles inline formatting
 // --------------------------------------------------------------------------------------
diff --git a/src/FSharp.Formatting/FSharp.Formatting.fsproj b/src/FSharp.Formatting/FSharp.Formatting.fsproj
index 1f0f340ed..fd2b4e4f0 100644
--- a/src/FSharp.Formatting/FSharp.Formatting.fsproj
+++ b/src/FSharp.Formatting/FSharp.Formatting.fsproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <IsPackable>true</IsPackable>
     <UsesMarkdownComments>true</UsesMarkdownComments>
   </PropertyGroup>
diff --git a/src/FSharp.Formatting/FSharp.Formatting.fsx b/src/FSharp.Formatting/FSharp.Formatting.fsx
index 2b2f1b587..e16428a58 100644
--- a/src/FSharp.Formatting/FSharp.Formatting.fsx
+++ b/src/FSharp.Formatting/FSharp.Formatting.fsx
@@ -1,11 +1,11 @@
 #nowarn "211"
 
 // FSharp.Formatting repo context: uncomment for intellisense
-//#I "bin/Release/netstandard2.1"
+//#I "bin/Release/netstandard2.0"
 
 // Standard NuGet or Paket location
 #I __SOURCE_DIRECTORY__
-#I "lib/netstandard2.1"
+#I "lib/netstandard2.0"
 
 // Standard Paket locations
 #I "../FSharp.Compiler.Service/lib/netstandard2.0"
diff --git a/tests/FSharp.ApiDocs.Tests/AttributeTests.fs b/tests/FSharp.ApiDocs.Tests/AttributeTests.fs
index 02bf41d15..7b51e43e4 100644
--- a/tests/FSharp.ApiDocs.Tests/AttributeTests.fs
+++ b/tests/FSharp.ApiDocs.Tests/AttributeTests.fs
@@ -27,7 +27,7 @@ let configuration =
     "Release"
 #endif
 
-let tfm = "netstandard2.1"
+let tfm = "netstandard2.0"
 
 // NOTE - For these tests to run properly they require the output of all the metadata
 // test project to be directed to the directory below
diff --git a/tests/FSharp.ApiDocs.Tests/files/AttributesTestLib/AttributesTestLib.fsproj b/tests/FSharp.ApiDocs.Tests/files/AttributesTestLib/AttributesTestLib.fsproj
index c2c78bec1..634c14c8b 100644
--- a/tests/FSharp.ApiDocs.Tests/files/AttributesTestLib/AttributesTestLib.fsproj
+++ b/tests/FSharp.ApiDocs.Tests/files/AttributesTestLib/AttributesTestLib.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <OutputPath>..\bin\$(Configuration)</OutputPath>
     <NoWarn>FS1182</NoWarn>
   </PropertyGroup>
diff --git a/tests/FSharp.ApiDocs.Tests/files/FsLib1/FsLib1.fsproj b/tests/FSharp.ApiDocs.Tests/files/FsLib1/FsLib1.fsproj
index 3098691d0..e48c0851b 100644
--- a/tests/FSharp.ApiDocs.Tests/files/FsLib1/FsLib1.fsproj
+++ b/tests/FSharp.ApiDocs.Tests/files/FsLib1/FsLib1.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <OutputPath>..\bin\$(Configuration)</OutputPath>
   </PropertyGroup>
   <ItemGroup>
diff --git a/tests/FSharp.ApiDocs.Tests/files/FsLib2/FsLib2.fsproj b/tests/FSharp.ApiDocs.Tests/files/FsLib2/FsLib2.fsproj
index c675160ae..fddc6f19f 100644
--- a/tests/FSharp.ApiDocs.Tests/files/FsLib2/FsLib2.fsproj
+++ b/tests/FSharp.ApiDocs.Tests/files/FsLib2/FsLib2.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <OutputPath>..\bin\$(Configuration)</OutputPath>
     <NoWarn>FS1182</NoWarn>
   </PropertyGroup>
diff --git a/tests/FSharp.ApiDocs.Tests/files/TestLib1/TestLib1.fsproj b/tests/FSharp.ApiDocs.Tests/files/TestLib1/TestLib1.fsproj
index 13ebd334f..30c813b49 100644
--- a/tests/FSharp.ApiDocs.Tests/files/TestLib1/TestLib1.fsproj
+++ b/tests/FSharp.ApiDocs.Tests/files/TestLib1/TestLib1.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <OutputPath>..\bin\$(Configuration)</OutputPath>
   </PropertyGroup>
   <ItemGroup>
diff --git a/tests/FSharp.ApiDocs.Tests/files/TestLib2/TestLib2.fsproj b/tests/FSharp.ApiDocs.Tests/files/TestLib2/TestLib2.fsproj
index f55d5dd2a..ee207621b 100644
--- a/tests/FSharp.ApiDocs.Tests/files/TestLib2/TestLib2.fsproj
+++ b/tests/FSharp.ApiDocs.Tests/files/TestLib2/TestLib2.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <OutputPath>..\bin\$(Configuration)</OutputPath>
   </PropertyGroup>
   <ItemGroup>
diff --git a/tests/FSharp.ApiDocs.Tests/files/TestLib3/TestLib3.fsproj b/tests/FSharp.ApiDocs.Tests/files/TestLib3/TestLib3.fsproj
index d16b794bf..514e8e15b 100644
--- a/tests/FSharp.ApiDocs.Tests/files/TestLib3/TestLib3.fsproj
+++ b/tests/FSharp.ApiDocs.Tests/files/TestLib3/TestLib3.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <OutputPath>..\bin\$(Configuration)</OutputPath>
   </PropertyGroup>
   <ItemGroup>
diff --git a/tests/FSharp.ApiDocs.Tests/files/crefLib1/crefLib1.fsproj b/tests/FSharp.ApiDocs.Tests/files/crefLib1/crefLib1.fsproj
index 0eb463dc1..3890cc90e 100644
--- a/tests/FSharp.ApiDocs.Tests/files/crefLib1/crefLib1.fsproj
+++ b/tests/FSharp.ApiDocs.Tests/files/crefLib1/crefLib1.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <OutputPath>..\bin\$(Configuration)</OutputPath>
   </PropertyGroup>
   <ItemGroup>
diff --git a/tests/FSharp.ApiDocs.Tests/files/crefLib2/crefLib2.fsproj b/tests/FSharp.ApiDocs.Tests/files/crefLib2/crefLib2.fsproj
index 66f4b7144..a08e9f7ea 100644
--- a/tests/FSharp.ApiDocs.Tests/files/crefLib2/crefLib2.fsproj
+++ b/tests/FSharp.ApiDocs.Tests/files/crefLib2/crefLib2.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <OutputPath>..\bin\$(Configuration)</OutputPath>
   </PropertyGroup>
   <ItemGroup>
diff --git a/tests/FSharp.ApiDocs.Tests/files/crefLib3/crefLib3.csproj b/tests/FSharp.ApiDocs.Tests/files/crefLib3/crefLib3.csproj
index 1a4e7e06d..6ea53cbcc 100644
--- a/tests/FSharp.ApiDocs.Tests/files/crefLib3/crefLib3.csproj
+++ b/tests/FSharp.ApiDocs.Tests/files/crefLib3/crefLib3.csproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <OutputPath>..\bin\$(Configuration)</OutputPath>
     <NoWarn>CS0067;CS1591;CS1574</NoWarn>
diff --git a/tests/FSharp.ApiDocs.Tests/files/crefLib4/crefLib4.csproj b/tests/FSharp.ApiDocs.Tests/files/crefLib4/crefLib4.csproj
index 54d4eef28..2f1d83b92 100644
--- a/tests/FSharp.ApiDocs.Tests/files/crefLib4/crefLib4.csproj
+++ b/tests/FSharp.ApiDocs.Tests/files/crefLib4/crefLib4.csproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <OutputPath>..\bin\$(Configuration)</OutputPath>
     <NoWarn>CS0067;CS1591;CS1574</NoWarn>
diff --git a/tests/FSharp.ApiDocs.Tests/files/csharpSupport/csharpSupport.csproj b/tests/FSharp.ApiDocs.Tests/files/csharpSupport/csharpSupport.csproj
index 1a4e7e06d..6ea53cbcc 100644
--- a/tests/FSharp.ApiDocs.Tests/files/csharpSupport/csharpSupport.csproj
+++ b/tests/FSharp.ApiDocs.Tests/files/csharpSupport/csharpSupport.csproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <OutputPath>..\bin\$(Configuration)</OutputPath>
     <NoWarn>CS0067;CS1591;CS1574</NoWarn>
diff --git a/tests/FSharp.Formatting.TestHelpers/FSharp.Formatting.TestHelpers.fsproj b/tests/FSharp.Formatting.TestHelpers/FSharp.Formatting.TestHelpers.fsproj
index 6d535f745..eedfc6509 100644
--- a/tests/FSharp.Formatting.TestHelpers/FSharp.Formatting.TestHelpers.fsproj
+++ b/tests/FSharp.Formatting.TestHelpers/FSharp.Formatting.TestHelpers.fsproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="AssemblyInfo.fs" />