diff --git a/sw/device/tests/BUILD b/sw/device/tests/BUILD
index 584ac714e4a8b..33eb874aada4d 100644
--- a/sw/device/tests/BUILD
+++ b/sw/device/tests/BUILD
@@ -2538,10 +2538,12 @@ cc_library(
 opentitan_test(
     name = "pwrmgr_all_reset_reqs_test",
     srcs = ["pwrmgr_all_reset_reqs_test.c"],
+    broken = new_cw310_params(tags = ["broken"]),
     exec_env = dicts.add(
         EARLGREY_SILICON_OWNER_ROM_EXT_ENVS,
         {
-            "//hw/top_earlgrey:fpga_cw310_sival_rom_ext": "test_harness",
+            # FIXME broken in sival ROM_EXT, remove this line when fixed. See #21706.
+            "//hw/top_earlgrey:fpga_cw310_sival_rom_ext": "broken",
             "//hw/top_earlgrey:fpga_cw310_sival": "test_harness",
             "//hw/top_earlgrey:fpga_cw310_test_rom": "test_harness",
             "//hw/top_earlgrey:silicon_creator": None,
@@ -2575,11 +2577,13 @@ opentitan_test(
 opentitan_test(
     name = "pwrmgr_random_sleep_all_reset_reqs_test",
     srcs = ["pwrmgr_random_sleep_all_reset_reqs_test.c"],
+    broken = new_cw310_params(tags = ["broken"]),
     exec_env = dicts.add(
         EARLGREY_SILICON_OWNER_ROM_EXT_ENVS,
         {
             "//hw/top_earlgrey:fpga_cw310_sival": "test_harness",
-            "//hw/top_earlgrey:fpga_cw310_sival_rom_ext": "test_harness",
+            # FIXME broken in sival ROM_EXT, remove this line when fixed. See #21706.
+            "//hw/top_earlgrey:fpga_cw310_sival_rom_ext": "broken",
             "//hw/top_earlgrey:fpga_cw310_test_rom": "test_harness",
             "//hw/top_earlgrey:silicon_creator": None,
             "//hw/top_earlgrey:sim_dv": None,