diff --git a/qiling/os/posix/syscall/unistd.py b/qiling/os/posix/syscall/unistd.py
index 62cb6f61a..204c9b84d 100644
--- a/qiling/os/posix/syscall/unistd.py
+++ b/qiling/os/posix/syscall/unistd.py
@@ -153,7 +153,7 @@ def ql_syscall_capset(ql: Qiling, hdrp: int, datap: int):
 
 def ql_syscall_kill(ql: Qiling, pid: int, sig: int):
     if sig not in range(NSIG):
-        return -1   # EINVAL
+        return -EINVAL
 
     if pid > 0 and pid != ql.os.pid:
         return -1   # ESRCH