diff --git a/linker/debugger.c b/linker/debugger.c
index 7a1dd15..dde66f3 100644
--- a/linker/debugger.c
+++ b/linker/debugger.c
@@ -156,7 +156,7 @@
  * Catches fatal signals so we can ask debuggerd to ptrace us before
  * we crash.
  */
-void debugger_signal_handler(int n, siginfo_t* info, void* unused)
+void debugger_signal_handler(int n, siginfo_t* info, void* unused __attribute__((unused)))
 {
     char msgbuf[128];
     unsigned tid;