diff --git a/rtl/bsd/x86_64/syscall.inc b/rtl/bsd/x86_64/syscall.inc
index 299bdab904..1b95196601 100644
--- a/rtl/bsd/x86_64/syscall.inc
+++ b/rtl/bsd/x86_64/syscall.inc
@@ -60,7 +60,7 @@ asm
   movq sysnr,%rax         { Syscall number -> rax.  }
   movq param1,%rdi        { shift arg1 - arg1. }
   syscall                 { Do the system call. }
-  jb .LSyscOK             { branch to exit if ok, errorhandler otherwise}
+  jnb .LSyscOK            { branch to exit if ok, errorhandler otherwise}
  movq  %rax,%rdx
 {$ifdef FPC_PIC}
   movq  fpc_threadvar_relocate_proc@GOTPCREL(%rip),%rax