diff --git a/README.md b/README.md
index a1fa374..c83fa72 100644
--- a/README.md
+++ b/README.md
@@ -1,25 +1,29 @@
 # pygbx
+
 A Python library to parse Gbx files, used in [TMTrackNN](https://github.com/donadigo/TMTrackNN) and other projects of mine that involve extracting
 useful data from Gbx files.
 
 # Examples
+
 (For more documentation, refer to the docstrings in the source files.)
 
 ## Read metadata about a Challenge map:
+
 ```python
 from pygbx import Gbx, GbxType
 
-g = Gbx('A01-Race.Challenge.Gbx')
-challenge = g.get_class_by_id(GbxType.CHALLENGE)
-if not challenge:
-    quit()
+with Gbx('A01-Race.Challenge.Gbx') as g:
+    challenge = g.get_class_by_id(GbxType.CHALLENGE)
+    if not challenge:
+        quit()
 
-print(f'Map Name: {challenge.map_name}')
-print(f'Map Author: {challenge.map_author}')
-print(f'Environment: {challenge.environment}')
+    print(f'Map Name: {challenge.map_name}')
+    print(f'Map Author: {challenge.map_author}')
+    print(f'Environment: {challenge.environment}')
 ```
 
 ### Output:
+
 ```
 Map Name: A01-Race
 Map Author: Nadeo
@@ -27,20 +31,22 @@ Environment: Stadium
 ```
 
 ## Enumerate blocks present in a Challenge map:
+
 ```python
 from pygbx import Gbx, GbxType
 
-g = Gbx('A-0.Challenge.Gbx')
-challenges = g.get_classes_by_ids([GbxType.CHALLENGE, GbxType.CHALLENGE_OLD])
-if not challenges:
-    quit()
+with Gbx('A-0.Challenge.Gbx') as g:
+    challenges = g.get_classes_by_ids([GbxType.CHALLENGE, GbxType.CHALLENGE_OLD])
+    if not challenges:
+        quit()
 
-challenge = challenges[0]
-for block in challenge.blocks:
-    print(block)
+    challenge = challenges[0]
+    for block in challenge.blocks:
+        print(block)
 ```
 
 ### Output:
+
 ```
 Name: StadiumRoadMainStartLine
 Rotation: 0
@@ -61,21 +67,23 @@ Flags: 0b1000000000000
 ```
 
 ## Read metadata about a ghost in a Replay:
+
 ```python
 from pygbx import Gbx, GbxType
 
-g = Gbx('A04_5_77.Replay.Gbx')
-ghost = g.get_class_by_id(GbxType.CTN_GHOST)
-if not ghost:
-    quit()
+with Gbx('A04_5_77.Replay.Gbx') as g:
+    ghost = g.get_class_by_id(GbxType.CTN_GHOST)
+    if not ghost:
+        quit()
 
-print(f'Race time: {ghost.race_time}')
-print(f'Num respawns: {ghost.num_respawns}')
-print(f'Game version: {ghost.game_version}')
-print(f'Map UID: {ghost.uid}')
+    print(f'Race time: {ghost.race_time}')
+    print(f'Num respawns: {ghost.num_respawns}')
+    print(f'Game version: {ghost.game_version}')
+    print(f'Map UID: {ghost.uid}')
 ```
 
 ### Output:
+
 ```
 Race time: 5770
 Num respawns: 0
diff --git a/pygbx/gbx.py b/pygbx/gbx.py
index f9ae431..16e1fc1 100644
--- a/pygbx/gbx.py
+++ b/pygbx/gbx.py
@@ -79,9 +79,15 @@ def __init__(self, obj):
         else:
             self.root_parser = ByteReader(obj)
 
-        self.magic = self.root_parser.read(3, '3s')
-        if self.magic.decode('utf-8') != 'GBX':
+        magic = self.root_parser.read(3, '3s')
+        try:
+            magic = magic.decode('utf-8')
+        except:
+            raise GbxLoadError(f'obj is not a valid Gbx data: can not decode unicode')
+
+        if magic != 'GBX':
             raise GbxLoadError(f'obj is not a valid Gbx data: magic string is incorrect')
+            
         self.version = self.root_parser.read(2, 'H')
         self.classes = {}
         self.root_classes = {}
@@ -125,7 +131,7 @@ def __init__(self, obj):
                     self.root_parser.skip(4)
 
         self.root_parser.push_info()
-        self.positions['data_size'] = self.root_parser.pop_info()
+        self.positions["data_size"] = self.root_parser.pop_info()
 
         data_size = self.root_parser.read_uint32()
         compressed_data_size = self.root_parser.read_uint32()
@@ -135,6 +141,17 @@ def __init__(self, obj):
         bp = ByteReader(self.data)
         self._read_node(self.class_id, -1, bp)
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exception_type, exception_value, exception_traceback):
+        self.close()
+
+    """Closes the current file connection."""
+    def close(self):
+        if self.f:
+            self.f.close()
+
     def __read_sub_folder(self):
         num_sub_folders = self.root_parser.read_uint32()
         for folder in range(num_sub_folders):