diff --git a/src/codegen.cpp b/src/codegen.cpp
index 4f100d75ad..00103be259 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;