diff --git a/src/codegen.cpp b/src/codegen.cpp
index 4f100d75ada1fa799e5885c87e9b9132524ed076..00103be259c7c911348e651f122a2f7bda00fd08 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -4373,6 +4373,7 @@ static LLVMValueRef gen_const_val(CodeGen *g, ConstExprValue *const_val, const c
                         }
                 }
             }
+            zig_unreachable();
         case TypeTableEntryIdErrorUnion:
             {
                 TypeTableEntry *payload_type = type_entry->data.error_union.payload_type;