diff --git a/tests/sys/kern/pdeathsig.c b/tests/sys/kern/pdeathsig.c
index 749f413d3635..34c9adef577c 100644
--- a/tests/sys/kern/pdeathsig.c
+++ b/tests/sys/kern/pdeathsig.c
@@ -229,6 +229,7 @@ ATF_TC_BODY(signal_delivered_ptrace, tc)
 	int rc;
 	int pipe_ca[2];
 	int pipe_db[2];
+	int pipe_cd[2];
 	char buffer;
 	int status;
 
@@ -236,6 +237,8 @@ ATF_TC_BODY(signal_delivered_ptrace, tc)
 	ATF_REQUIRE(rc == 0);
 	rc = pipe(pipe_db);
 	ATF_REQUIRE(rc == 0);
+	rc = pipe(pipe_cd);
+	assert(rc == 0);
 
 	rc = fork();
 	ATF_REQUIRE(rc != -1);
@@ -263,6 +266,9 @@ ATF_TC_BODY(signal_delivered_ptrace, tc)
 			rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
 			assert(rc == 0);
 
+			rc = write(pipe_cd[1], "x", 1);
+			assert(rc == 1);
+
 			/* wait for B to die and signal us... */
 			signum = 0xdeadbeef;
 			rc = sigwait(&sigset, &signum);
@@ -293,6 +299,9 @@ ATF_TC_BODY(signal_delivered_ptrace, tc)
 			rc = ptrace(PT_CONTINUE, c_pid, (caddr_t) 1, 0);
 			assert(rc == 0);
 
+			rc = read(pipe_cd[0], &buffer, 1);
+			assert(rc == 1);
+
 			/* tell B that we're ready for it to exit now */
 			rc = write(pipe_db[1], ".", 1);
 			assert(rc == 1);