diff --git a/sins/mutation.py b/sins/mutation.py
index 22cf192..625ec5b 100644
--- a/sins/mutation.py
+++ b/sins/mutation.py
@@ -60,7 +60,9 @@ def growth(*, shellcode: bytes, length: int) -> bytes:
 
     opcodes = disasm(shellcode)
 
-    if len(shellcode) > len(opcodes) * 8:
+    max_op_len = 15
+
+    if len(shellcode) > len(opcodes) * max_op_len:
         return bytes(shellcode)
 
     for mnemonic, op_str in opcodes: