diff --git a/src/compiler/sys.ts b/src/compiler/sys.ts
index 5dc4fbe91cc35..69651c64439ca 100644
--- a/src/compiler/sys.ts
+++ b/src/compiler/sys.ts
@@ -1186,7 +1186,6 @@ namespace ts {
             let activeSession: import("inspector").Session | "stopping" | undefined;
             let profilePath = "./profile.cpuprofile";
 
-            const realpathSync = _fs.realpathSync.native ?? _fs.realpathSync;
 
             const Buffer: {
                 new (input: string, encoding?: string): any;
@@ -1199,6 +1198,8 @@ namespace ts {
 
             const platform: string = _os.platform();
             const useCaseSensitiveFileNames = isFileSystemCaseSensitive();
+            const realpathSync = useCaseSensitiveFileNames ? _fs.realpathSync : (_fs.realpathSync.native ?? _fs.realpathSync);
+
             const fsSupportsRecursiveFsWatch = isNode4OrLater && (process.platform === "win32" || process.platform === "darwin");
             const getCurrentDirectory = memoize(() => process.cwd());
             const { watchFile, watchDirectory } = createSystemWatchFunctions({