diff --git a/cli/logging.ts b/cli/logging.ts
index aeb1f9e3770..c58bab77d41 100644
--- a/cli/logging.ts
+++ b/cli/logging.ts
@@ -8,32 +8,35 @@ export const stderr = (...parameters: readonly unknown[]) =>
 	process.stderr.write(`${parameters.join('')}\n`);
 
 export function handleError(error: RollupError, recover = false): void {
-	const name = error.name || error.cause?.name;
+	const name = error.name || (error.cause as Error)?.name;
 	const nameSection = name ? `${name}: ` : '';
 	const pluginSection = error.plugin ? `(plugin ${error.plugin}) ` : '';
 	const message = `${pluginSection}${nameSection}${error.message}`;
 
-	stderr(bold(red(`[!] ${bold(message.toString())}`)));
+	const outputLines = [bold(red(`[!] ${bold(message.toString())}`))];
 
 	if (error.url) {
-		stderr(cyan(error.url));
+		outputLines.push(cyan(error.url));
 	}
 
 	if (error.loc) {
-		stderr(`${relativeId((error.loc.file || error.id)!)} (${error.loc.line}:${error.loc.column})`);
+		outputLines.push(
+			`${relativeId((error.loc.file || error.id)!)} (${error.loc.line}:${error.loc.column})`
+		);
 	} else if (error.id) {
-		stderr(relativeId(error.id));
+		outputLines.push(relativeId(error.id));
 	}
 
 	if (error.frame) {
-		stderr(dim(error.frame));
+		outputLines.push(dim(error.frame));
 	}
 
 	if (error.stack) {
-		stderr(dim(error.stack));
+		outputLines.push(dim(error.stack?.replace(`${nameSection}${error.message}\n`, '')));
 	}
 
-	stderr('');
+	outputLines.push('', '');
+	stderr(outputLines.join('\n'));
 
 	// eslint-disable-next-line unicorn/no-process-exit
 	if (!recover) process.exit(1);
diff --git a/src/ast/variables/ExportDefaultVariable.ts b/src/ast/variables/ExportDefaultVariable.ts
index e2ecada0204..7d31cefab03 100644
--- a/src/ast/variables/ExportDefaultVariable.ts
+++ b/src/ast/variables/ExportDefaultVariable.ts
@@ -37,6 +37,15 @@ export default class ExportDefaultVariable extends LocalVariable {
 		}
 	}
 
+	forbidName(name: string) {
+		const original = this.getOriginalVariable();
+		if (original === this) {
+			super.forbidName(name);
+		} else {
+			original.forbidName(name);
+		}
+	}
+
 	getAssignedVariableName(): string | null {
 		return (this.originalId && this.originalId.name) || null;
 	}
diff --git a/src/rollup/types.d.ts b/src/rollup/types.d.ts
index 1c35370a821..103e6b6e9e5 100644
--- a/src/rollup/types.d.ts
+++ b/src/rollup/types.d.ts
@@ -19,7 +19,7 @@ export type RollupWarning = RollupLog;
 
 export interface RollupLog {
 	binding?: string;
-	cause?: Error;
+	cause?: unknown;
 	code?: string;
 	exporter?: string;
 	frame?: string;
diff --git a/test/cli/samples/custom-frame-with-pos/_config.js b/test/cli/samples/custom-frame-with-pos/_config.js
index e778c6418a4..2af0a903e4d 100644
--- a/test/cli/samples/custom-frame-with-pos/_config.js
+++ b/test/cli/samples/custom-frame-with-pos/_config.js
@@ -7,9 +7,6 @@ module.exports = {
 	stderr: stderr =>
 		assertIncludes(
 			stderr,
-			'[!] (plugin at position 1) Error: My error.\n' +
-				'main.js (1:5)\n' +
-				'custom code frame\n' +
-				'Error: My error.'
+			'[!] (plugin at position 1) Error: My error.\n' + 'main.js (1:5)\n' + 'custom code frame\n'
 		)
 };
diff --git a/test/cli/samples/custom-frame/_config.js b/test/cli/samples/custom-frame/_config.js
index 6754f50bfe2..bd3f7c35c69 100644
--- a/test/cli/samples/custom-frame/_config.js
+++ b/test/cli/samples/custom-frame/_config.js
@@ -8,7 +8,7 @@ module.exports = {
 		assertIncludes(
 			stderr,
 			'[!] (plugin at position 1) Error: My error.\n' +
-				'main.js\ncustom code frame\nError: My error.\n' +
+				'main.js\ncustom code frame\n' +
 				'    at Object.'
 		);
 		assertIncludes(stderr, 'rollup.config.js:9:19');
diff --git a/test/cli/samples/watch/bundle-error/_config.js b/test/cli/samples/watch/bundle-error/_config.js
index f8a2ebeab1a..c00b2e0161b 100644
--- a/test/cli/samples/watch/bundle-error/_config.js
+++ b/test/cli/samples/watch/bundle-error/_config.js
@@ -16,7 +16,7 @@ module.exports = {
 		setTimeout(() => unlinkSync(mainFile), 300);
 	},
 	abortOnStderr(data) {
-		if (data.includes('Error: Unexpected token')) {
+		if (data.includes('[!] RollupError: Unexpected token')) {
 			setTimeout(() => atomicWriteFileSync(mainFile, 'export default 42;'), 500);
 			return false;
 		}
diff --git a/test/function/samples/class-name-conflict2/_config.js b/test/function/samples/class-name-conflict-2/_config.js
similarity index 100%
rename from test/function/samples/class-name-conflict2/_config.js
rename to test/function/samples/class-name-conflict-2/_config.js
diff --git a/test/function/samples/class-name-conflict2/bar.js b/test/function/samples/class-name-conflict-2/bar.js
similarity index 100%
rename from test/function/samples/class-name-conflict2/bar.js
rename to test/function/samples/class-name-conflict-2/bar.js
diff --git a/test/function/samples/class-name-conflict2/declaration.js b/test/function/samples/class-name-conflict-2/declaration.js
similarity index 100%
rename from test/function/samples/class-name-conflict2/declaration.js
rename to test/function/samples/class-name-conflict-2/declaration.js
diff --git a/test/function/samples/class-name-conflict2/expression.js b/test/function/samples/class-name-conflict-2/expression.js
similarity index 100%
rename from test/function/samples/class-name-conflict2/expression.js
rename to test/function/samples/class-name-conflict-2/expression.js
diff --git a/test/function/samples/class-name-conflict2/foo.js b/test/function/samples/class-name-conflict-2/foo.js
similarity index 100%
rename from test/function/samples/class-name-conflict2/foo.js
rename to test/function/samples/class-name-conflict-2/foo.js
diff --git a/test/function/samples/class-name-conflict2/main.js b/test/function/samples/class-name-conflict-2/main.js
similarity index 100%
rename from test/function/samples/class-name-conflict2/main.js
rename to test/function/samples/class-name-conflict-2/main.js
diff --git a/test/function/samples/class-name-conflict-3/_config.js b/test/function/samples/class-name-conflict-3/_config.js
new file mode 100644
index 00000000000..922cad01591
--- /dev/null
+++ b/test/function/samples/class-name-conflict-3/_config.js
@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'does not shadow variables when preserving class names'
+};
diff --git a/test/function/samples/class-name-conflict-3/foo.js b/test/function/samples/class-name-conflict-3/foo.js
new file mode 100644
index 00000000000..7804111002d
--- /dev/null
+++ b/test/function/samples/class-name-conflict-3/foo.js
@@ -0,0 +1 @@
+export default class Foo {}
diff --git a/test/function/samples/class-name-conflict-3/main.js b/test/function/samples/class-name-conflict-3/main.js
new file mode 100644
index 00000000000..22b9b90b33a
--- /dev/null
+++ b/test/function/samples/class-name-conflict-3/main.js
@@ -0,0 +1,14 @@
+import Bar from './foo';
+
+const wrapper = () => {
+	class Foo extends Bar {
+		static assertName() {
+			assert.strictEqual(this.name, 'Foo');
+			assert.strictEqual(super.name, 'Foo');
+		}
+	}
+
+	return Foo;
+};
+
+wrapper().assertName();
diff --git a/test/function/samples/class-name-conflict-4/_config.js b/test/function/samples/class-name-conflict-4/_config.js
new file mode 100644
index 00000000000..922cad01591
--- /dev/null
+++ b/test/function/samples/class-name-conflict-4/_config.js
@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'does not shadow variables when preserving class names'
+};
diff --git a/test/function/samples/class-name-conflict-4/foo.js b/test/function/samples/class-name-conflict-4/foo.js
new file mode 100644
index 00000000000..03e6dcc163e
--- /dev/null
+++ b/test/function/samples/class-name-conflict-4/foo.js
@@ -0,0 +1,5 @@
+var Foo = class {};
+
+export default Foo;
+
+Foo = 'reassigned';
diff --git a/test/function/samples/class-name-conflict-4/main.js b/test/function/samples/class-name-conflict-4/main.js
new file mode 100644
index 00000000000..70152e988cc
--- /dev/null
+++ b/test/function/samples/class-name-conflict-4/main.js
@@ -0,0 +1,14 @@
+import Bar from './reexport';
+
+const wrapper = () => {
+	class Foo extends Bar {
+		static assertName() {
+			assert.strictEqual(this.name, 'Foo');
+			assert.strictEqual(super.name, 'Foo');
+		}
+	}
+
+	return Foo;
+};
+
+wrapper().assertName();
diff --git a/test/function/samples/class-name-conflict-4/reexport.js b/test/function/samples/class-name-conflict-4/reexport.js
new file mode 100644
index 00000000000..ee90f7e3084
--- /dev/null
+++ b/test/function/samples/class-name-conflict-4/reexport.js
@@ -0,0 +1,2 @@
+import Foo from './foo';
+export default Foo;