diff --git a/ToolsTales.py b/ToolsTales.py
index cd4fcb4..79432e2 100644
--- a/ToolsTales.py
+++ b/ToolsTales.py
@@ -404,18 +404,6 @@ class ToolsTales:
     
         # Didn't match anything
         return None
-    
-    def is_compressed(self,data):
-        if len(data) < 0x09:
-            return False
-    
-        expected_size = struct.unpack("<L", data[1:5])[0]
-        tail_data = abs(len(data) - (expected_size + 9))
-        if expected_size == len(data) - 9:
-            return True
-        elif tail_data <= 0x10 and data[expected_size + 9 :] == b"#" * tail_data:
-            return True # SCPK files have these trailing "#" bytes :(
-        return False
 
 
     def extract_Cab(self, cab_file_name, new_file_name, working_dir):
diff --git a/comptolib.py b/comptolib.py
index d0bc5e4..9a8c478 100644
--- a/comptolib.py
+++ b/comptolib.py
@@ -101,4 +101,20 @@ def compress_file(input: str, output: str, raw: bool=False, version: int=3):
 
 def decompress_file(input: str, output: str, raw: bool=False, version: int=3):
     error = compto_fdecode(input.encode("utf-8"), output.encode("utf-8"), raw, version)
-    RaiseError(error)
\ No newline at end of file
+    RaiseError(error)
+
+
+def is_compressed(data: bytes) -> bool:
+    if len(data) < 0x09:
+        return False
+
+    expected_size = struct.unpack("<L", data[1:5])[0]
+    tail_data = abs(len(data) - (expected_size + 9))
+
+    if expected_size == len(data) - 9:
+        return True
+
+    if tail_data <= 0x10 and data[expected_size + 9 :] == b"#" * tail_data:
+        return True  # SCPK files have these trailing "#" bytes :(
+
+    return False