diff --git a/user/usys.py b/user/usys.py
index 677c5b8..f17f05d 100755
--- a/user/usys.py
+++ b/user/usys.py
@@ -10,8 +10,8 @@ template = """
 
 
 def genstub(syscall: str):
-    if not 3 >= len(syscall) <= 15:
-        raise ValueError("Syscall {} is too short/long!".format(syscall[:35]))
+    if not 3 <= len(syscall) <= 15:
+        raise ValueError("Syscall {name} is too short/long!".format(name=syscall[:35]))
 
     return template.format(name=syscall)