diff --git a/hw/vendor/lowrisc_ibex/rtl/ibex_top.sv b/hw/vendor/lowrisc_ibex/rtl/ibex_top.sv
index 8991c17251ee3c..8a18b7d6e0789a 100644
--- a/hw/vendor/lowrisc_ibex/rtl/ibex_top.sv
+++ b/hw/vendor/lowrisc_ibex/rtl/ibex_top.sv
@@ -148,7 +148,7 @@ module ibex_top import ibex_pkg::*; #(
   localparam bit          Lockstep              = SecureIbex;
   localparam bit          ResetAll              = Lockstep;
   localparam bit          DummyInstructions     = SecureIbex;
-  localparam bit          RegFileECC            = SecureIbex;
+  localparam bit          RegFileECC            = 1'b0;
   localparam bit          RegFileWrenCheck      = SecureIbex;
   localparam bit          RegFileRdataMuxCheck  = SecureIbex;
   localparam int unsigned RegFileDataWidth      = RegFileECC ? 32 + 7 : 32;
diff --git a/sw/device/tests/BUILD b/sw/device/tests/BUILD
index 804cfacafb97ee..81bec9d5b28bed 100644
--- a/sw/device/tests/BUILD
+++ b/sw/device/tests/BUILD
@@ -2599,14 +2599,14 @@ opentitan_test(
     name = "otbn_mem_scramble_test",
     srcs = ["otbn_mem_scramble_test.c"],
     exec_env = dicts.add(
-        EARLGREY_TEST_ENVS,
         EARLGREY_SILICON_OWNER_ROM_EXT_ENVS,
         {
+            "//hw/top_earlgrey:fpga_cw340_sival": None,
             "//hw/top_earlgrey:silicon_creator": None,
+            "//hw/top_earlgrey:sim_dv": None,
+            "//hw/top_earlgrey:sim_verilator": None,
         },
     ),
-    # TODO(#12486) [bazel] targets in sw/device/tests failing on cw310 and verilator when built by bazel
-    fpga = fpga_params(tags = ["broken"]),
     verilator = verilator_params(timeout = "long"),
     deps = [
         "//hw/top_earlgrey/sw/autogen:top_earlgrey",