diff --git a/test/zdtm/live/static/ptrace_sig.c b/test/zdtm/live/static/ptrace_sig.c
index 83dbf02af..0058e46e4 100644
--- a/test/zdtm/live/static/ptrace_sig.c
+++ b/test/zdtm/live/static/ptrace_sig.c
@@ -30,7 +30,7 @@ void sig_chld_handler(int signo)
 	test_msg("Receive signal %d\n", signo);
 }
 
-int child(fd)
+int child(int fd)
 {
 	int ret = 0;
 	struct sigaction act = {