diff --git a/src/FhirOperationDefinitionGen/FhirOperationDefinitionGen.csproj b/src/FhirOperationDefinitionGen/FhirOperationDefinitionGen.csproj
index 21ac7bd..af407c8 100644
--- a/src/FhirOperationDefinitionGen/FhirOperationDefinitionGen.csproj
+++ b/src/FhirOperationDefinitionGen/FhirOperationDefinitionGen.csproj
@@ -12,7 +12,7 @@
     <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
     <PackageReference Include="Hl7.Fhir.R4" Version="5.7.0" PrivateAssets="all"
       GeneratePathProperty="true" />
-    <PackageReference Include="Hl7.Fhir.Base" Version="5.7.0" PrivateAssets="all"
+    <PackageReference Include="Hl7.Fhir.Base" Version="6.1.0" PrivateAssets="all"
       GeneratePathProperty="true" />
     <PackageReference Include="Scriban" Version="5.9.1" PrivateAssets="all"
       GeneratePathProperty="true" />