diff --git a/src/GitVersionCore.Tests/BuildServers/VsoAgentBuildNumberTests.cs b/src/GitVersionCore.Tests/BuildServers/VsoAgentBuildNumberTests.cs
new file mode 100644
index 0000000000..83d50cf6ff
--- /dev/null
+++ b/src/GitVersionCore.Tests/BuildServers/VsoAgentBuildNumberTests.cs
@@ -0,0 +1,67 @@
+using System;
+using GitVersion;
+using GitVersionCore.Tests;
+using NUnit.Framework;
+using Shouldly;
+using System.Collections.Generic;
+
+[TestFixture]
+public class VsoAgentBuildNumberTests
+{
+    string key = "BUILD_BUILDNUMBER";
+    string logPrefix = "##vso[build.updatebuildnumber]";
+    List<Tuple<string, string, string>> examples;
+    VsoAgent versionBuilder = new VsoAgent();
+
+    [SetUp]
+    public void SetUpVsoAgentBuildNumberTest()
+    {
+         examples = new List<Tuple<string, string, string>>();
+    }
+
+    [TearDown]
+    public void TearDownVsoAgentBuildNumberTest()
+    {
+        examples = null;
+        Environment.SetEnvironmentVariable(key, null, EnvironmentVariableTarget.Process);
+    }
+
+
+    [Test]
+    public void VsoAgentBuildNumberWithFullSemVer()
+    {
+        examples.Add(new Tuple<string, string, string>("$(GitVersion.FullSemVer)", "1.0.0", "1.0.0"));
+        examples.Add(new Tuple<string, string, string>("$(GITVERSION_FULLSEMVER)", "1.0.0", "1.0.0"));
+        examples.Add(new Tuple<string, string, string>("$(GitVersion.FullSemVer)-Build.1234", "1.0.0", "1.0.0-Build.1234"));
+        examples.Add(new Tuple<string, string, string>("$(GITVERSION_FULLSEMVER)-Build.1234", "1.0.0", "1.0.0-Build.1234"));
+
+        foreach (var example in examples)
+        {
+            Environment.SetEnvironmentVariable(key, example.Item1, EnvironmentVariableTarget.Process);
+            var vars = new TestableVersionVariables(fullSemVer: example.Item2);
+
+            var logMessage = versionBuilder.GenerateSetVersionMessage(vars);
+            logMessage.ShouldBe(logPrefix + example.Item3);
+        }
+    }
+
+
+    [Test]
+    public void VsoAgentBuildNumberWithSemVer()
+    {
+        examples.Add(new Tuple<string, string, string>("$(GitVersion.SemVer)", "1.0.0", "1.0.0"));
+        examples.Add(new Tuple<string, string, string>("$(GITVERSION_SEMVER)", "1.0.0", "1.0.0"));
+        examples.Add(new Tuple<string, string, string>("$(GitVersion.SemVer)-Build.1234", "1.0.0", "1.0.0-Build.1234"));
+        examples.Add(new Tuple<string, string, string>("$(GITVERSION_SEMVER)-Build.1234", "1.0.0", "1.0.0-Build.1234"));
+
+        foreach (var example in examples)
+        {
+            Environment.SetEnvironmentVariable(key, example.Item1, EnvironmentVariableTarget.Process);
+            var vars = new TestableVersionVariables(semVer: example.Item2);
+
+            var logMessage = versionBuilder.GenerateSetVersionMessage(vars);
+            logMessage.ShouldBe(logPrefix + example.Item3);
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/src/GitVersionCore.Tests/GitVersionCore.Tests.csproj b/src/GitVersionCore.Tests/GitVersionCore.Tests.csproj
index a3c44e6cc2..370f750929 100644
--- a/src/GitVersionCore.Tests/GitVersionCore.Tests.csproj
+++ b/src/GitVersionCore.Tests/GitVersionCore.Tests.csproj
@@ -90,6 +90,7 @@
     <Compile Include="BuildServers\GitLabCiMessageGenerationTest.cs" />
     <Compile Include="BuildServers\JenkinsMessageGenerationTests.cs" />
     <Compile Include="BuildServers\MyGetTests.cs" />
+    <Compile Include="BuildServers\VsoAgentBuildNumberTests.cs" />
     <Compile Include="BuildServers\VsoAgentTests.cs" />
     <Compile Include="BuildServers\TeamCityTests.cs" />
     <Compile Include="Configuration\IgnoreConfigTests.cs" />
diff --git a/src/GitVersionCore/BuildServers/VsoAgent.cs b/src/GitVersionCore/BuildServers/VsoAgent.cs
index 8a0457dccc..b629a4d9c9 100644
--- a/src/GitVersionCore/BuildServers/VsoAgent.cs
+++ b/src/GitVersionCore/BuildServers/VsoAgent.cs
@@ -36,7 +36,7 @@ public override string GenerateSetVersionMessage(VersionVariables variables)
             var buildNum = Environment.GetEnvironmentVariable("BUILD_BUILDNUMBER");
 
             var newBuildNum = variables.Aggregate(buildNum, (current, kvp) =>
-                current.RegexReplace(string.Format(@"\$\(GITVERSION_{0}\)", kvp.Key), kvp.Value ?? string.Empty, RegexOptions.IgnoreCase));
+                current.RegexReplace(string.Format(@"\$\(GITVERSION[_\.]{0}\)", kvp.Key), kvp.Value ?? string.Empty, RegexOptions.IgnoreCase));
 
             // If no variable substitution has happened, use FullSemVer
             if (buildNum == newBuildNum)