1 files changed, 4 insertions, 1 deletions
diff --git a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
index 539b9a9d..b7aafe1a 100644
--- a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
+++ b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
@@ -750,7 +750,10 @@ public class TypeChecker {
                 }
 
                 case UntypedSumTypeDefinitionNode untypedSumTypeDefinition -> {
-                    throw new UnsupportedOperationException("TODO");
+                    dependencyChecker = dependencyChecker.addDeferredDependencies(
+                        untypedSumTypeDefinition.name(),
+                        Set.of()
+                    );
                 }
             }
         }