diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index d7822bf..0250739 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -22,7 +22,9 @@ jobs:
         DOTNET_CLI_TELEMETRY_OPTOUT: 1
 
     steps:
-    - uses: actions/checkout@v2
+    - name: Checkout source code
+      uses: actions/checkout@v2
+
     - name: Setup dotnet 2.1
       uses: actions/setup-dotnet@v1
       with:
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index d8e87c3..13b9c31 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -14,15 +14,27 @@ jobs:
         DOTNET_CLI_TELEMETRY_OPTOUT: 1
 
     steps:
-    - uses: actions/checkout@v2
-    - name: Setup .NET Core
+    - name: Checkout source code
+      uses: actions/checkout@v2
+
+    - name: Setup dotnet 2.1
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: 2.1.*
+
+    - name: Setup dotnet 3.1
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: 3.1.*
+
+    - name: Setup dotnet 5.0
       uses: actions/setup-dotnet@v1
       with:
         dotnet-version: 5.0.*
-    - name: Install dependencies
-      run: dotnet restore
+
     - name: Test
-      run: dotnet test -c Release --framework net5.0
+      run: dotnet test --configuration Release
+
     - name: Pack with dotnet
       run: |
         arrTag=(${GITHUB_REF//\// })
@@ -30,5 +42,6 @@ jobs:
         VERSION="${VERSION//v}"
         echo "$VERSION"
         dotnet pack --output artifacts --configuration Release -p:Version=$VERSION
+
     - name: Push with dotnet
       run: dotnet nuget push artifacts/*.nupkg --api-key ${{ secrets.NUGET_API_KEY }} --source https://api.nuget.org/v3/index.json
diff --git a/src/Parlot/Character.cs b/src/Parlot/Character.cs
index fd21b76..f31a96e 100644
--- a/src/Parlot/Character.cs
+++ b/src/Parlot/Character.cs
@@ -180,7 +180,7 @@ private static string CreateString<TState>(int length, TState state, SpanAction<
 
             action(array, state);
 
-            return array.ToString();
+            return new string(array);
         }
 #endif
     }
diff --git a/src/Parlot/Fluent/DecimalLiteral.cs b/src/Parlot/Fluent/DecimalLiteral.cs
index 3b86e9d..5b97ab8 100644
--- a/src/Parlot/Fluent/DecimalLiteral.cs
+++ b/src/Parlot/Fluent/DecimalLiteral.cs
@@ -38,7 +38,7 @@ public override bool Parse(ParseContext context, ref ParseResult<decimal> result
             {
                 var end = context.Scanner.Cursor.Offset;
 #if NETSTANDARD2_0
-                var sourceToParse = context.Scanner.Buffer.ToString();
+                var sourceToParse = context.Scanner.Buffer.Substring(start, end -start);
 #else
                 var sourceToParse = context.Scanner.Buffer.AsSpan(start, end - start);
 #endif
diff --git a/src/Parlot/Fluent/IntegerLiteral.cs b/src/Parlot/Fluent/IntegerLiteral.cs
index 3bbf85e..9c8bc94 100644
--- a/src/Parlot/Fluent/IntegerLiteral.cs
+++ b/src/Parlot/Fluent/IntegerLiteral.cs
@@ -39,7 +39,7 @@ public override bool Parse(ParseContext context, ref ParseResult<long> result)
                 var end = context.Scanner.Cursor.Offset;
 
 #if NETSTANDARD2_0
-                var sourceToParse = context.Scanner.Buffer.ToString();
+                var sourceToParse = context.Scanner.Buffer.Substring(start, end - start);
 #else
                 var sourceToParse = context.Scanner.Buffer.AsSpan(start, end - start);
 #endif
diff --git a/test/Parlot.Tests/Parlot.Tests.csproj b/test/Parlot.Tests/Parlot.Tests.csproj
index 2064e6d..bdf63bd 100644
--- a/test/Parlot.Tests/Parlot.Tests.csproj
+++ b/test/Parlot.Tests/Parlot.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net5.0;netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.1;net5.0;netcoreapp3.1</TargetFrameworks>
     <IsPackable>false</IsPackable>
     <LangVersion>9.0</LangVersion>
   </PropertyGroup>