diff --git a/ccgen/generation.py b/ccgen/generation.py
index 315bca1..c830846 100644
--- a/ccgen/generation.py
+++ b/ccgen/generation.py
@@ -27,6 +27,14 @@ def generate_enum(self, enum: Enum):
             for name, value in enum.items.items():
                 arr += f'    "{name}",\n'
             arr += "};\n"
+
+            maximum = max(enum.items.values())
+            minimum = min(enum.items.values())
+
             self.header.append(f"{decl};")
             self.source.append(arr)
-            self.source.append(f"{decl}\n{{\n    return {array_name}[e];\n}}")
+            self.source.append(f"{decl}\n{{")
+            self.source.append(f"    int index = e - {minimum};")
+            self.source.append(f"    assert(e >= {minimum} && e <= {maximum});")
+            self.source.append(f"    return {array_name}[index];")
+            self.source.append(f"}}")
diff --git a/ccgen/parser.py b/ccgen/parser.py
index 16aaa80..2082ef6 100644
--- a/ccgen/parser.py
+++ b/ccgen/parser.py
@@ -1,4 +1,6 @@
 from dataclasses import dataclass, field
+import enum
+from sys import stderr
 from typing import Iterable, List
 
 from strictyaml import YAML
@@ -18,12 +20,20 @@ def visit_enums(self, node: YAML):
             e = Enum(str(enum_name), {})
             self.enums.append(e)
 
-            attributes = self.visit_attributes(enum_def["attributes"])
-            for attr in attributes:
-                f = getattr(self, f"process_enum_attribute_{attr}")
-                f(e)
+            if 'attributes' in enum_def:
+                attributes = self.visit_attributes(enum_def["attributes"])
+                for attr in attributes:
+                    f = getattr(self, f"process_enum_attribute_{attr}")
+                    f(e)
 
-            items = self.visit_items(enum_def["items"], e)
+            if enum_def.is_sequence():
+                yaml_items = enum_def
+            elif 'items' in enum_def:
+                yaml_items = enum_def["items"]
+            else:
+                print("Enums without items/values are not permitted.")
+
+            items = self.visit_items(yaml_items, e)
             e.items = items
 
     def process_enum_attribute_bits(self, enum: Enum):
diff --git a/ccgen/types.py b/ccgen/types.py
index 88b90c5..3c69f39 100644
--- a/ccgen/types.py
+++ b/ccgen/types.py
@@ -8,7 +8,7 @@
 @dataclass
 class Enum:
     name: str
-    items: Dict[str, Optional[int]] = field(default_factory=dict)
+    items: Dict[str, int] = field(default_factory=dict)
 
     is_bits: bool = False
     is_stringable: bool = False
diff --git a/pyproject.toml b/pyproject.toml
index 2dd50c2..5b0600d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [project]
 name = "ccgen"
 description = "Simple C code generator for enums."
-version = "0.1.2"
+version = "0.1.3"
 classifiers = [
     "License :: OSI Approved :: MIT License",
 ]
diff --git a/test/test_01.yml b/test/test_01.yml
index f7e1f99..60a3462 100644
--- a/test/test_01.yml
+++ b/test/test_01.yml
@@ -1,4 +1,11 @@
 enums:
+  Test0:
+    - Head
+ 
+  Test1:
+    items:
+      - Head
+      
   ItemType:
     attributes:
       - bits