diff --git a/contrib/netbsd-tests/lib/libpthread/t_mutex.c b/contrib/netbsd-tests/lib/libpthread/t_mutex.c
index bcb8540f5679..3b8c8b72c727 100644
--- a/contrib/netbsd-tests/lib/libpthread/t_mutex.c
+++ b/contrib/netbsd-tests/lib/libpthread/t_mutex.c
@@ -153,6 +153,12 @@ ATF_TC_HEAD(mutex2, tc)
 	atf_tc_set_md_var(tc, "timeout", "40");
 #endif
 #endif
+
+#ifdef __FreeBSD__
+#if defined(__riscv)
+	atf_tc_set_md_var(tc, "timeout", "600");
+#endif
+#endif
 }
 ATF_TC_BODY(mutex2, tc)
 {
@@ -230,6 +236,12 @@ ATF_TC_HEAD(mutex3, tc)
 	atf_tc_set_md_var(tc, "timeout", "40");
 #endif
 #endif
+
+#ifdef __FreeBSD__
+#if defined(__riscv)
+	atf_tc_set_md_var(tc, "timeout", "600");
+#endif
+#endif
 }
 ATF_TC_BODY(mutex3, tc)
 {