diff --git a/src/libos/src/syscall/mod.rs b/src/libos/src/syscall/mod.rs
index 180c3f80..072dbdd3 100644
--- a/src/libos/src/syscall/mod.rs
+++ b/src/libos/src/syscall/mod.rs
@@ -307,7 +307,7 @@ pub extern "C" fn dispatch_syscall(
             warn!("{}", e.backtrace());
 
             let retval = -(e.errno() as isize);
-            debug_assert!(retval == 0);
+            debug_assert!(retval != 0);
             retval
         }
     }