diff --git a/tests/TestHelper.cs b/tests/TestHelper.cs
index e3509ab..669ac03 100644
--- a/tests/TestHelper.cs
+++ b/tests/TestHelper.cs
@@ -52,9 +52,9 @@ static TestHelper ()
 
 			var dir = Path.GetDirectoryName (codeBase);
 
-			while (!string.Equals (Path.GetFileName (dir), "tests", StringComparison.Ordinal)) {
+			while (!IsTestsProjectDir (dir)) {
 				var candidate = Path.Combine (dir, "tests");
-				if (Directory.Exists (candidate)) {
+				if (Directory.Exists (candidate) && IsTestsProjectDir (candidate)) {
 					dir = candidate;
 					break;
 				}
@@ -68,5 +68,11 @@ static TestHelper ()
 
 			ProjectDir = Path.GetFullPath (dir);
 		}
+
+		static bool IsTestsProjectDir (string dir)
+		{
+			return string.Equals (Path.GetFileName (dir), "tests", StringComparison.Ordinal)
+				&& File.Exists (Path.Combine (dir, "tests.csproj"));
+		}
 	}
 }
diff --git a/tests/tests.csproj b/tests/tests.csproj
index 6c60994..5e221d0 100644
--- a/tests/tests.csproj
+++ b/tests/tests.csproj
@@ -1,10 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>net472;net10.0</TargetFrameworks>
+    <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('windows'))">net472;net10.0</TargetFrameworks>
+    <TargetFrameworks Condition="!$([MSBuild]::IsOSPlatform('windows'))">net10.0</TargetFrameworks>
     <LangVersion>latest</LangVersion>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
     <IsShipping>false</IsShipping>
   </PropertyGroup>
   <ItemGroup>