diff --git a/packages/configtest/src/index.ts b/packages/configtest/src/index.ts
index 8f66fdbaccc..d7c0bc37700 100644
--- a/packages/configtest/src/index.ts
+++ b/packages/configtest/src/index.ts
@@ -11,6 +11,8 @@ class ConfigTestCommand {
             },
             [],
             async (configPath: string | undefined): Promise<void> => {
+                cli.webpack = await cli.loadWebpack();
+
                 const config = await cli.resolveConfig(configPath ? { config: [configPath] } : {});
                 const configPaths = new Set<string>();
 
@@ -33,18 +35,19 @@ class ConfigTestCommand {
 
                 cli.logger.info(`Validate '${Array.from(configPaths).join(" ,")}'.`);
 
-                const webpack = await cli.loadWebpack();
-
                 try {
                     // eslint-disable-next-line @typescript-eslint/no-explicit-any
-                    const error: any = webpack.validate(config.options);
+                    const error: any = cli.webpack.validate(config.options);
 
                     // TODO remove this after drop webpack@4
                     if (error && error.length > 0) {
-                        throw new webpack.WebpackOptionsValidationError(error);
+                        throw new cli.webpack.WebpackOptionsValidationError(error);
                     }
                 } catch (error) {
-                    if (cli.isValidationError(error)) {
+                    if (
+                        error instanceof cli.webpack.ValidationError ||
+                        error.name === "ValidationError"
+                    ) {
                         cli.logger.error(error.message);
                     } else {
                         cli.logger.error(error);