diff --git a/regress/agent-ptrace.sh b/regress/agent-ptrace.sh
index 9aff167..4de2638 100644
--- a/regress/agent-ptrace.sh
+++ b/regress/agent-ptrace.sh
@@ -41,7 +41,7 @@
 	if [ $? -ne 0 ]; then
 		fail "gdb failed: exit code $?"
 	fi
-	egrep 'ptrace: Operation not permitted.|procfs:.*Permission denied.|ttrace attach: Permission denied.' >/dev/null ${OBJ}/gdb.out
+	egrep 'ptrace: Operation not permitted.|procfs:.*Permission denied.|ttrace attach: Permission denied.|procfs:.*: Invalid argument.' >/dev/null ${OBJ}/gdb.out
 	r=$?
 	rm -f ${OBJ}/gdb.out
 	if [ $r -ne 0 ]; then