diff --git a/packages/http-client-csharp/emitter/src/lib/client-model-builder.ts b/packages/http-client-csharp/emitter/src/lib/client-model-builder.ts
index 15c4da86c86..6f9ec8d1db4 100644
--- a/packages/http-client-csharp/emitter/src/lib/client-model-builder.ts
+++ b/packages/http-client-csharp/emitter/src/lib/client-model-builder.ts
@@ -99,8 +99,8 @@ function fixNamingConflicts(models: InputModelType[], constants: InputLiteralTyp
         type.namespace = model.namespace;
         type.access = model.access;
         type.usage = model.usage;
-      } else if (type.kind === "enum" && type.crossLanguageDefinitionId === "") {
-        // Fix enum names for enums created from constants
+      } else if (type.kind === "enum" && (type.crossLanguageDefinitionId === "" || type.name === "")) {
+        // Fix enum names for enums created from constants or anonymous unions
         type.name = `${model.name}${firstLetterToUpperCase(property.name)}`;
         type.namespace = model.namespace;
         type.access = model.access;