diff --git a/src/Hocon.Immutable/Hocon.Immutable.csproj b/src/Hocon.Immutable/Hocon.Immutable.csproj
index 768aaccd..bcd535d7 100644
--- a/src/Hocon.Immutable/Hocon.Immutable.csproj
+++ b/src/Hocon.Immutable/Hocon.Immutable.csproj
@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="System.Collections.Immutable" Version="1.7.1" />
+    <PackageReference Include="System.Collections.Immutable" Version="5.0.0" />
   </ItemGroup>
 
   <ItemGroup>