diff --git a/example3.json b/example3.json
new file mode 100644
index 0000000..fc15e6d
--- /dev/null
+++ b/example3.json
@@ -0,0 +1,105 @@
+{
+    "structures": {
+        "main": {
+            "bits": 32,
+            "ranges": {
+                "31-28": {
+                    "name": "cond"
+                },
+                "27": {
+                    "name": "0"
+                },
+                "26": {
+                    "name": "1"
+                },
+                "25": {
+                    "name": "I"
+                },
+                "24": {
+                    "name": "P",
+                    "description": "pre / post indexing bit",
+                    "values": {
+                        "0": "post, add offset after transfer",
+                        "1": "pre, add offset before transfer"
+                    }
+                },
+                "23": {
+                    "name": "U",
+                    "description": "up / down bit",
+                    "values": {
+                        "0": "down, subtract offset from base",
+                        "1": "up, addition offset to base"
+                    }
+                },
+                "22": {
+                    "name": "B",
+                    "description": "byte / word bit",
+                    "values": {
+                        "0": "transfer word quantity",
+                        "1": "transfer byte quantity"
+                    }
+                },
+                "21": {
+                    "name": "W",
+                    "description": "write-back bit",
+                    "values": {
+                        "0": "no write-back",
+                        "1": "write address into base"
+                    }
+                },
+                "20": {
+                    "name": "L",
+                    "description": "load / store bit",
+                    "values": {
+                        "0": "store to memory",
+                        "1": "load from memory"
+                    }
+                },
+                "19-16": {
+                    "name": "Rn",
+                    "description": "base register"
+                },
+                "15-12": {
+                    "name": "Rd",
+                    "description": "source / destination register"
+                },
+                "11-0": {
+                    "name": "offset",
+                    "depends-on": "25",
+                    "values": {
+                        "0": {
+                            "description": "offset is an immediate value",
+                            "structure": "immediateOffset"
+                        },
+                        "1": {
+                            "description": "offset is a register",
+                            "structure": "registerOffset"
+                        }
+                    }
+                }
+            }
+        },
+        "immediateOffset": {
+            "bits": 12,
+            "ranges": {
+                "11-0": {
+                    "name": "12-bit immediate offset",
+                    "description": "unsigned number"
+                }
+            }
+        },
+        "registerOffset": {
+            "bits": 12,
+            "ranges": {
+                "11-4": {
+                    "name": "shift",
+                    "description": "shift applied to Rm"
+                },
+                "3-0": {
+                    "name": "Rm",
+                    "description": "offset register"
+                }
+            }
+        }
+    }
+}
diff --git a/schema.py b/schema.py
index 2ccaa3e..7a4cec8 100644
--- a/schema.py
+++ b/schema.py
@@ -1,18 +1,36 @@
+import json
+import os
 import yaml
 
 from config import Config
 from renderer import Renderer
 from structure import Structure
 
+class UnsupportedFormatException(Exception):
+    ...
+
 class InstructionSetSchema:
+    VALID_EXTENSIONS = ("yaml", "json")
+    
     def __init__(self, path: str, configPath: str = "config.json") -> None:
         self.config = Config(configPath)
         self.path = path
         self.load()
     
     def load(self) -> None:
+        _, ext = os.path.splitext(self.path)
+        ext = ext[1:].lower()
+        
+        if ext not in InstructionSetSchema.VALID_EXTENSIONS:
+            fmts = tuple(map(lambda fmt: f".{fmt}", InstructionSetSchema.VALID_EXTENSIONS))
+            raise UnsupportedFormatException(f"'.{ext}' files are not supported. Valid formats: {fmts}")
+        
         with open(self.path, "r") as f:
-            schema = yaml.safe_load(f)
+            if ext == "yaml":
+                schema = yaml.safe_load(f)
+        
+            elif ext == "json":
+                schema = json.load(f)
 
         self.structures = {}