diff --git a/src/ast/nodes/MemberExpression.ts b/src/ast/nodes/MemberExpression.ts
index 8d88d357ef3..7bf2bcd2301 100644
--- a/src/ast/nodes/MemberExpression.ts
+++ b/src/ast/nodes/MemberExpression.ts
@@ -258,17 +258,18 @@ export default class MemberExpression extends NodeBase implements DeoptimizableE
 	}
 
 	private disallowNamespaceReassignment() {
-		if (
-			this.object instanceof Identifier &&
-			this.scope.findVariable(this.object.name).isNamespace
-		) {
-			return this.context.error(
-				{
-					code: 'ILLEGAL_NAMESPACE_REASSIGNMENT',
-					message: `Illegal reassignment to import '${this.object.name}'`
-				},
-				this.start
-			);
+		if (this.object instanceof Identifier) {
+			const variable = this.scope.findVariable(this.object.name);
+			if (variable.isNamespace) {
+				variable.include();
+				this.context.warn(
+					{
+						code: 'ILLEGAL_NAMESPACE_REASSIGNMENT',
+						message: `Illegal reassignment to import '${this.object.name}'`
+					},
+					this.start
+				);
+			}
 		}
 	}
 
diff --git a/test/function/samples/namespace-reassign-import-fails/_config.js b/test/function/samples/namespace-reassign-import-fails/_config.js
index 3ab81beb7bd..677971b7ade 100644
--- a/test/function/samples/namespace-reassign-import-fails/_config.js
+++ b/test/function/samples/namespace-reassign-import-fails/_config.js
@@ -1,24 +1,26 @@
 const path = require('path');
 
 module.exports = {
-	description: 'disallows reassignments to namespace exports',
-	error: {
-		code: 'ILLEGAL_NAMESPACE_REASSIGNMENT',
-		message: `Illegal reassignment to import 'exp'`,
-		pos: 31,
-		watchFiles: [path.resolve(__dirname, 'main.js'), path.resolve(__dirname, 'foo.js')],
-		loc: {
-			file: path.resolve(__dirname, 'main.js'),
-			line: 3,
-			column: 0
-		},
-		frame: `
+	description: 'warns for reassignments to namespace exports',
+	warnings: [
+		{
+			code: 'ILLEGAL_NAMESPACE_REASSIGNMENT',
+			message: `Illegal reassignment to import 'exp'`,
+			id: path.resolve(__dirname, 'main.js'),
+			pos: 31,
+			loc: {
+				file: path.resolve(__dirname, 'main.js'),
+				line: 3,
+				column: 0
+			},
+			frame: `
 			1: import * as exp from './foo';
 			2:
 			3: exp.foo = 2;
 			   ^
 		`
-	}
+		}
+	]
 };
 
 // test copied from https://github.com/esnext/es6-module-transpiler/tree/master/test/examples/namespace-reassign-import-fails
diff --git a/test/function/samples/namespace-update-import-fails/_config.js b/test/function/samples/namespace-update-import-fails/_config.js
index f5d608e7ffd..4c3da7877e6 100644
--- a/test/function/samples/namespace-update-import-fails/_config.js
+++ b/test/function/samples/namespace-update-import-fails/_config.js
@@ -2,23 +2,25 @@ const path = require('path');
 
 module.exports = {
 	description: 'disallows updates to namespace exports',
-	error: {
-		code: 'ILLEGAL_NAMESPACE_REASSIGNMENT',
-		message: `Illegal reassignment to import 'exp'`,
-		pos: 31,
-		watchFiles: [path.resolve(__dirname, 'main.js'), path.resolve(__dirname, 'foo.js')],
-		loc: {
-			file: path.resolve(__dirname, 'main.js'),
-			line: 3,
-			column: 0
-		},
-		frame: `
+	warnings: [
+		{
+			code: 'ILLEGAL_NAMESPACE_REASSIGNMENT',
+			message: `Illegal reassignment to import 'exp'`,
+			id: path.resolve(__dirname, 'main.js'),
+			pos: 31,
+			loc: {
+				file: path.resolve(__dirname, 'main.js'),
+				line: 3,
+				column: 0
+			},
+			frame: `
 			1: import * as exp from './foo';
 			2:
 			3: exp['foo']++;
 			   ^
 		`
-	}
+		}
+	]
 };
 
 // test copied from https://github.com/esnext/es6-module-transpiler/tree/master/test/examples/namespace-update-import-fails