diff --git a/tests/bootstrap_test.sh b/tests/bootstrap_test.sh
index 2331eb15b..ba5ba8bf9 100755
--- a/tests/bootstrap_test.sh
+++ b/tests/bootstrap_test.sh
@@ -547,7 +547,6 @@ function test_bp2build_smoke {
 
 function test_bp2build_generates_marker_file {
   setup
-  create_mock_bazel
 
   run_soong bp2build
 
diff --git a/tests/bp2build_bazel_test.sh b/tests/bp2build_bazel_test.sh
index ad21d7d89..679ac557c 100755
--- a/tests/bp2build_bazel_test.sh
+++ b/tests/bp2build_bazel_test.sh
@@ -50,7 +50,6 @@ test_bp2build_null_build_with_globs
 
 function test_different_relative_outdir {
   setup
-  create_mock_bazel
 
   mkdir -p a
   touch a/g.txt
@@ -73,7 +72,6 @@ test_different_relative_outdir
 
 function test_different_absolute_outdir {
   setup
-  create_mock_bazel
 
   mkdir -p a
   touch a/g.txt
@@ -96,7 +94,6 @@ test_different_absolute_outdir
 
 function test_bp2build_generates_all_buildfiles {
   setup
-  create_mock_bazel
 
   mkdir -p foo/convertible_soong_module
   cat > foo/convertible_soong_module/Android.bp <<'EOF'
@@ -167,7 +164,6 @@ eval ${_save_trap}
 
 function test_cc_correctness {
   setup
-  create_mock_bazel
 
   mkdir -p a
   cat > a/Android.bp <<EOF
diff --git a/tests/lib.sh b/tests/lib.sh
index 006186ad1..e40f0adda 100644
--- a/tests/lib.sh
+++ b/tests/lib.sh
@@ -82,10 +82,10 @@ function symlink_directory {
 }
 
 function create_mock_soong {
+  create_mock_bazel
   copy_directory build/blueprint
   copy_directory build/soong
   copy_directory build/make/tools/rbcrun
-  copy_directory prebuilts/bazel/common/proto
 
   symlink_directory prebuilts/sdk
   symlink_directory prebuilts/go
diff --git a/tests/mixed_mode_test.sh b/tests/mixed_mode_test.sh
index 076ec4b54..8949b428a 100755
--- a/tests/mixed_mode_test.sh
+++ b/tests/mixed_mode_test.sh
@@ -12,7 +12,6 @@ source "$(dirname "$0")/lib.sh"
 
 function test_bazel_smoke {
   setup
-  create_mock_bazel
 
   run_soong bp2build
 
@@ -21,7 +20,6 @@ function test_bazel_smoke {
 
 function test_add_irrelevant_file {
   setup
-  create_mock_bazel
 
   mkdir -p soong_tests/a/b
   touch soong_tests/a/b/c.txt
@@ -33,7 +31,7 @@ filegroup {
 }
 EOF
 
-  run_soong --bazel-mode nothing
+  run_soong --bazel-mode-staging nothing
 
   if [[ ! -e out/soong/bp2build/soong_tests/a/b/BUILD.bazel ]]; then
     fail "BUILD.bazel not created"
@@ -48,7 +46,7 @@ EOF
 
   touch soong_tests/a/irrelevant.txt
 
-  run_soong --bazel-mode nothing
+  run_soong --bazel-mode-staging nothing
   local mtime_build2=$(stat -c "%y" out/soong/bp2build/soong_tests/a/b/BUILD.bazel)
   local mtime_ninja2=$(stat -c "%y" out/soong/build.ninja)
 
diff --git a/ui/build/config.go b/ui/build/config.go
index 36119f0f1..b38f23092 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -236,6 +236,21 @@ func loadEnvConfig(ctx Context, config *configImpl) error {
 	return nil
 }
 
+func defaultBazelProdMode(cfg *configImpl) bool {
+	// Envirnoment flag to disable Bazel for users which experience
+	// broken bazel-handled builds, or significant performance regressions.
+	if cfg.IsBazelMixedBuildForceDisabled() {
+		return false
+	}
+	// Darwin-host builds are currently untested with Bazel.
+	if runtime.GOOS == "darwin" {
+		return false
+	}
+	// TODO(b/255364055): Flip this to true to enable bazel-mode by default
+	// for all users that don't opt out with BUILD_BROKEN_DISABLE_BAZEL.
+	return false
+}
+
 func NewConfig(ctx Context, args ...string) Config {
 	ret := &configImpl{
 		environ:       OsEnvironment(),
@@ -774,6 +789,9 @@ func (c *configImpl) parseArgs(ctx Context, args []string) {
 			c.arguments = append(c.arguments, arg)
 		}
 	}
+	if (!c.bazelProdMode) && (!c.bazelDevMode) && (!c.bazelStagingMode) {
+		c.bazelProdMode = defaultBazelProdMode(c)
+	}
 }
 
 func (c *configImpl) configureLocale(ctx Context) {
diff --git a/ui/build/config_test.go b/ui/build/config_test.go
index 968544be7..940d85c55 100644
--- a/ui/build/config_test.go
+++ b/ui/build/config_test.go
@@ -90,7 +90,9 @@ func TestConfigParseArgsJK(t *testing.T) {
 				t.Fatal(err)
 			})
 
+			env := Environment([]string{})
 			c := &configImpl{
+				environ:   &env,
 				parallel:  -1,
 				keepGoing: -1,
 			}