diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index ec7547bdda89..7ac63821a884 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -2125,7 +2125,8 @@ signal_address_tests()
 		pm_nl_add_endpoint $ns1 10.0.3.1 flags signal
 		pm_nl_add_endpoint $ns1 10.0.4.1 flags signal
 		pm_nl_set_limits $ns2 3 3
-		run_tests $ns1 $ns2 10.0.1.1
+		speed=slow \
+			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 3 3 3
 		chk_add_nr 3 3
 	fi
@@ -2137,7 +2138,8 @@ signal_address_tests()
 		pm_nl_add_endpoint $ns1 10.0.3.1 flags signal
 		pm_nl_add_endpoint $ns1 10.0.14.1 flags signal
 		pm_nl_set_limits $ns2 3 3
-		run_tests $ns1 $ns2 10.0.1.1
+		speed=slow \
+			run_tests $ns1 $ns2 10.0.1.1
 		join_syn_tx=3 \
 			chk_join_nr 1 1 1
 		chk_add_nr 3 3