diff --git a/test/AisParserTests/AisParserTests.csproj b/test/AisParserTests/AisParserTests.csproj
index 01b2d42..2b0880b 100644
--- a/test/AisParserTests/AisParserTests.csproj
+++ b/test/AisParserTests/AisParserTests.csproj
@@ -8,7 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="Bogus" Version="33.0.2" />
-    <PackageReference Include="JsonSubTypes" Version="1.8.0" />
+    <PackageReference Include="JsonSubTypes" Version="1.9.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.1" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="Shouldly" Version="4.0.3" />