diff --git a/litebox_platform_windows_userland/src/lib.rs b/litebox_platform_windows_userland/src/lib.rs
index beecdade7..54ace3320 100644
--- a/litebox_platform_windows_userland/src/lib.rs
+++ b/litebox_platform_windows_userland/src/lib.rs
@@ -462,6 +462,7 @@ unsafe extern "C-unwind" fn run_thread_inner(
     // At entry, the register context is the guest context with the
     // return address in rcx. r11 is an available scratch register (it would
     // contain rflags if the syscall instruction had actually been issued).
+    .globl  syscall_callback
 syscall_callback:
     // Get the TLS state from the TLS slot and clear the in-guest flag.
     mov     r11d, DWORD PTR [rip + {TLS_INDEX}]
@@ -928,6 +929,15 @@ impl litebox::platform::PunchthroughToken for PunchthroughToken {
                 eprintln!("WARNING: ignoring RtSigprocmask punchthrough");
                 Ok(0)
             }
+            PunchthroughSyscall::RtSigaction {
+                signum,
+                act: _,
+                oldact: _,
+            } => {
+                // Ignored for now.
+                eprintln!("WARNING: ignoring RtSigaction punchthrough for signum={signum:?}");
+                Ok(0)
+            }
             p => {
                 unimplemented!("unimplemented PunchthroughToken for WindowsUserland: {p:?}");
             }