diff --git a/w4c-workflows-api.csproj b/w4c-workflows-api.csproj
index f2c6c3d..833ec9b 100644
--- a/w4c-workflows-api.csproj
+++ b/w4c-workflows-api.csproj
@@ -8,6 +8,13 @@
     <AssemblyName>w4c-workflows-api</AssemblyName>
   </PropertyGroup>
 
+  <!-- Exclude the test project directory from default SDK globbing (tests live
+       inside this repo as a sibling directory, not a project reference). -->
+  <ItemGroup>
+    <Compile Remove="w4c-workflows-api.Tests/**" />
+    <None Remove="w4c-workflows-api.Tests/**" />
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="11.0.0-preview.6.26359.118" />
     <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="11.0.0-preview.6.26359.118" />