diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index a4257a610e1..e5b7d9a8152 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -842,6 +842,7 @@ namespace ts {
       */
     export function parseJsonConfigFileContent(json: any, host: ParseConfigHost, basePath: string, existingOptions: CompilerOptions = {}, configFileName?: string, resolutionStack: Path[] = [], extraFileExtensions: FileExtensionInfo[] = []): ParsedCommandLine {
         const errors: Diagnostic[] = [];
+        basePath = normalizeSlashes(basePath);
         const getCanonicalFileName = createGetCanonicalFileName(host.useCaseSensitiveFileNames);
         const resolvedPath = toPath(configFileName || "", basePath, getCanonicalFileName);
         if (resolutionStack.indexOf(resolvedPath) >= 0) {