diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6ae0ac2e763..c9131748129 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+* Fix internal error with `--supported:object-accessors=false` ([#3794](https://github.com/evanw/esbuild/issues/3794))
+
+    This release fixes a regression in 0.21.0 where some code that was added to esbuild's internal runtime library of helper functions for JavaScript decorators fails to parse when you configure esbuild with `--supported:object-accessors=false`. The reason is that esbuild introduced code that does `{ get [name]() {} }` which uses both the `object-extensions` feature for the `[name]` and the `object-accessors` feature for the `get`, but esbuild was incorrectly only checking for `object-extensions` and not for `object-accessors`. Additional tests have been added to avoid this type of issue in the future. A workaround for this issue in earlier releases is to also add `--supported:object-extensions=false`.
+
 ## 0.21.4
 
 * Update support for import assertions and import attributes in node ([#3778](https://github.com/evanw/esbuild/issues/3778))
diff --git a/internal/runtime/runtime.go b/internal/runtime/runtime.go
index b3bf41616f1..a56c7bed444 100644
--- a/internal/runtime/runtime.go
+++ b/internal/runtime/runtime.go
@@ -280,7 +280,7 @@ func Source(unsupportedJSFeatures compat.JSFeature) logger.Source {
 			`
 
 	// Avoid object extensions when not using ES6
-	if !unsupportedJSFeatures.Has(compat.ObjectExtensions) {
+	if !unsupportedJSFeatures.Has(compat.ObjectExtensions) && !unsupportedJSFeatures.Has(compat.ObjectAccessors) {
 		text += `__getOwnPropDesc(k < 4 ? target : { get [name]() { return __privateGet(this, extra) }, set [name](x) { return __privateSet(this, extra, x) } }, name)`
 	} else {
 		text += `(k < 4 ? __getOwnPropDesc(target, name) : { get: () => __privateGet(this, extra), set: x => __privateSet(this, extra, x) })`
diff --git a/internal/runtime/runtime_test.go b/internal/runtime/runtime_test.go
new file mode 100644
index 00000000000..108b2da4654
--- /dev/null
+++ b/internal/runtime/runtime_test.go
@@ -0,0 +1,33 @@
+package runtime_test
+
+import (
+	"testing"
+
+	"github.com/evanw/esbuild/internal/compat"
+	"github.com/evanw/esbuild/internal/config"
+	"github.com/evanw/esbuild/internal/js_parser"
+	"github.com/evanw/esbuild/internal/logger"
+	"github.com/evanw/esbuild/internal/runtime"
+)
+
+func TestUnsupportedFeatures(t *testing.T) {
+	for key, feature := range compat.StringToJSFeature {
+		t.Run(key, func(t *testing.T) {
+			source := runtime.Source(feature)
+			log := logger.NewDeferLog(logger.DeferLogAll, nil)
+
+			js_parser.Parse(log, source, js_parser.OptionsFromConfig(&config.Options{
+				UnsupportedJSFeatures: feature,
+				TreeShaking:           true,
+			}))
+
+			if log.HasErrors() {
+				msgs := "Internal error: failed to parse runtime:\n"
+				for _, msg := range log.Done() {
+					msgs += msg.String(logger.OutputOptions{IncludeSource: true}, logger.TerminalInfo{})
+				}
+				t.Fatal(msgs[:len(msgs)-1])
+			}
+		})
+	}
+}