diff --git a/src/installer/tests/HostActivation.Tests/InstallLocationCommandResultExtensions.cs b/src/installer/tests/HostActivation.Tests/InstallLocationCommandResultExtensions.cs
index 71d2616007c66..c85b7d3e56cc5 100644
--- a/src/installer/tests/HostActivation.Tests/InstallLocationCommandResultExtensions.cs
+++ b/src/installer/tests/HostActivation.Tests/InstallLocationCommandResultExtensions.cs
@@ -7,6 +7,7 @@
 using FluentAssertions;
 using Microsoft.DotNet.Cli.Build.Framework;
 using Microsoft.DotNet.CoreSetup.Test;
+using Xunit;
 
 namespace HostActivation.Tests
 {
@@ -14,16 +15,20 @@ internal static class InstallLocationCommandResultExtensions
     {
         private static bool IsRunningInWoW64(string rid) => OperatingSystem.IsWindows() && Environment.Is64BitOperatingSystem && rid.Equals("win-x86");
 
-        public static AndConstraint<CommandResultAssertions> HaveUsedDotNetRootInstallLocation(this CommandResultAssertions assertion, string installLocation)
+        public static AndConstraint<CommandResultAssertions> HaveUsedDotNetRootInstallLocation(this CommandResultAssertions assertion, string installLocation, string rid)
         {
-            return assertion.HaveUsedDotNetRootInstallLocation(installLocation, null, null);
+            return assertion.HaveUsedDotNetRootInstallLocation(installLocation, rid, null);
         }
 
         public static AndConstraint<CommandResultAssertions> HaveUsedDotNetRootInstallLocation(this CommandResultAssertions assertion,
             string installLocation,
-            string arch,
-            string rid)
+            string rid,
+            string arch)
         {
+            // If no arch is passed and we are on Windows, we need the used RID for determining whether or not we are running on WoW64.
+            if (string.IsNullOrEmpty(arch))
+                Assert.NotNull(rid);
+
             string expectedEnvironmentVariable = !string.IsNullOrEmpty(arch) ? $"DOTNET_ROOT_{arch.ToUpper()}" :
                 IsRunningInWoW64(rid) ? "DOTNET_ROOT(x86)" : "DOTNET_ROOT";
 
diff --git a/src/installer/tests/HostActivation.Tests/MultiArchInstallLocation.cs b/src/installer/tests/HostActivation.Tests/MultiArchInstallLocation.cs
index d12efb7a5cfbd..c1b00cafd4e6a 100644
--- a/src/installer/tests/HostActivation.Tests/MultiArchInstallLocation.cs
+++ b/src/installer/tests/HostActivation.Tests/MultiArchInstallLocation.cs
@@ -33,7 +33,7 @@ public void EnvironmentVariable_CurrentArchitectureIsUsedIfEnvVarSet()
                 .DotNetRoot(fixture.BuiltDotnet.BinPath, arch)
                 .Execute()
                 .Should().Pass()
-                .And.HaveUsedDotNetRootInstallLocation(fixture.BuiltDotnet.BinPath, arch, fixture.CurrentRid);
+                .And.HaveUsedDotNetRootInstallLocation(fixture.BuiltDotnet.BinPath, fixture.CurrentRid, arch);
         }
 
         [Fact]
@@ -49,7 +49,7 @@ public void EnvironmentVariable_IfNoArchSpecificEnvVarIsFoundDotnetRootIsUsed()
                 .DotNetRoot(fixture.BuiltDotnet.BinPath)
                 .Execute()
                 .Should().Pass()
-                .And.HaveUsedDotNetRootInstallLocation(fixture.BuiltDotnet.BinPath);
+                .And.HaveUsedDotNetRootInstallLocation(fixture.BuiltDotnet.BinPath, fixture.CurrentRid);
         }
 
         [Fact]
@@ -67,7 +67,7 @@ public void EnvironmentVariable_ArchSpecificDotnetRootIsUsedOverDotnetRoot()
                 .DotNetRoot(dotnet, arch)
                 .Execute()
                 .Should().Pass()
-                .And.HaveUsedDotNetRootInstallLocation(dotnet, arch, fixture.CurrentRid)
+                .And.HaveUsedDotNetRootInstallLocation(dotnet, fixture.CurrentRid, arch)
                 .And.NotHaveStdErrContaining("Using environment variable DOTNET_ROOT=");
         }