diff --git a/src/sly/sly.csproj b/src/sly/sly.csproj
index a17b2858..113003be 100644
--- a/src/sly/sly.csproj
+++ b/src/sly/sly.csproj
@@ -37,7 +37,7 @@
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
     <PackageReference Include="Newtonsoft.Json" Version="13.0.2"/>
-    <PackageReference Include="System.Collections.Immutable" Version="8.0.0"/>
+    <PackageReference Include="System.Collections.Immutable" Version="7.0.0"/>
     <PackageReference Include="System.Memory" Version="4.5.5"/>
     <PackageReference Include="System.ValueTuple" Version="4.5.0"/>
     <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4">