diff --git a/.github/workflows/build-push-nuget.yml b/.github/workflows/build-push-nuget.yml
index 06d97dd..6c21ed6 100644
--- a/.github/workflows/build-push-nuget.yml
+++ b/.github/workflows/build-push-nuget.yml
@@ -9,14 +9,14 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     defaults:
       run:
         working-directory: .
     name: Update NuGet package
     env:
         PACKAGE_PROJECT: NLog.Slack
-        TEST_PROJECT:
+        TEST_PROJECT: NLog.Slack.Tests
     steps:
 
       - name: Checkout repository
diff --git a/NLog.Slack.Tests/NLog.Slack.Tests.csproj b/NLog.Slack.Tests/NLog.Slack.Tests.csproj
index 663cd38..ce9a803 100644
--- a/NLog.Slack.Tests/NLog.Slack.Tests.csproj
+++ b/NLog.Slack.Tests/NLog.Slack.Tests.csproj
@@ -35,12 +35,6 @@
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="FluentAssertions">
-      <HintPath>..\packages\FluentAssertions.3.1.229\lib\net45\FluentAssertions.dll</HintPath>
-    </Reference>
-    <Reference Include="FluentAssertions.Core">
-      <HintPath>..\packages\FluentAssertions.3.1.229\lib\net45\FluentAssertions.Core.dll</HintPath>
-    </Reference>
     <Reference Include="Microsoft.CSharp" />
     <Reference Include="Moq">
       <HintPath>..\packages\Moq.4.2.1408.0717\lib\net40\Moq.dll</HintPath>
diff --git a/NLog.Slack.Tests/SlackTargetTests.cs b/NLog.Slack.Tests/SlackTargetTests.cs
index 1db998d..9e05160 100644
--- a/NLog.Slack.Tests/SlackTargetTests.cs
+++ b/NLog.Slack.Tests/SlackTargetTests.cs
@@ -1,5 +1,4 @@
 using System;
-using FluentAssertions;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
 namespace NLog.Slack.Tests
@@ -12,8 +11,8 @@ public void DefaultSettings_ShouldBeCorrect()
         {
             var slackTarget = new TestableSlackTarget();
 
-            slackTarget.Compact.Should().Be(false);
-            slackTarget.WebHookUrl.Should().Be(null);
+            Assert.IsFalse(slackTarget.Compact);
+            Assert.IsNull(slackTarget.WebHookUrl);
         }
 
         [TestMethod]
@@ -30,8 +29,8 @@ public void CustomSettings_ShouldBeCorrect()
 
             var logEvent = new LogEventInfo { Level = LogLevel.Info, Message = "This is a ${level} message" };
 
-            slackTarget.Compact.Should().Be(compact);
-            slackTarget.WebHookUrl.Should().Be(webHookUrl);
+            Assert.AreEqual(slackTarget.Compact, compact);
+            Assert.AreEqual(slackTarget.WebHookUrl, webHookUrl);
         }
 
         [TestMethod, ExpectedException(typeof(ArgumentOutOfRangeException))]
diff --git a/NLog.Slack.Tests/packages.config b/NLog.Slack.Tests/packages.config
index 454368f..00bcaf7 100644
--- a/NLog.Slack.Tests/packages.config
+++ b/NLog.Slack.Tests/packages.config
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="FluentAssertions" version="3.1.229" targetFramework="net45" />
   <package id="Moq" version="4.2.1408.0717" targetFramework="net45" />
   <package id="NLog" version="4.5.0" targetFramework="net45" />
 </packages>
\ No newline at end of file