diff --git a/db_stress_tool/db_stress_test_base.cc b/db_stress_tool/db_stress_test_base.cc
index daaa66f92cb..c79c0e237a1 100644
--- a/db_stress_tool/db_stress_test_base.cc
+++ b/db_stress_tool/db_stress_test_base.cc
@@ -2693,7 +2693,9 @@ void StressTest::Open(SharedState* shared, bool reopen) {
 
     // If this is for DB reopen, write error injection may have been enabled.
     // Disable it here in case there is no open fault injection.
-    fault_fs_guard->DisableWriteErrorInjection();
+    if (fault_fs_guard) {
+      fault_fs_guard->DisableWriteErrorInjection();
+    }
     if (!FLAGS_use_txn) {
       // Determine whether we need to inject file metadata write failures
       // during DB reopen. If it does, enable it.
diff --git a/tools/db_crashtest.py b/tools/db_crashtest.py
index 09bb11d1a00..49e9094f116 100644
--- a/tools/db_crashtest.py
+++ b/tools/db_crashtest.py
@@ -179,7 +179,7 @@
     "max_key_len": 3,
     "key_len_percent_dist": "1,30,69",
     "read_fault_one_in": lambda: random.choice([0, 32, 1000]),
-    "write_fault_one_in": lambda: random.choice([0, 500]),
+    "write_fault_one_in": 0,
     "open_metadata_write_fault_one_in": lambda: random.choice([0, 0, 8]),
     "open_write_fault_one_in": lambda: random.choice([0, 0, 16]),
     "open_read_fault_one_in": lambda: random.choice([0, 0, 32]),
@@ -681,7 +681,7 @@ def finalize_and_sanitize(src_params):
         dest_params["verify_file_checksums_one_in"] = 0
     if dest_params["write_fault_one_in"] > 0:
         # background work may be disabled while DB is resuming after some error
-        dest_params["max_write_buffer_number"] = max(dest_params["max_write_buffer_number"], 6)
+        dest_params["max_write_buffer_number"] = max(dest_params["max_write_buffer_number"], 10)
     return dest_params