diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index f0220fb8c93..a65298f72fe 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -1762,6 +1762,10 @@ namespace ts {
         return compareComparableValues(a, b);
     }
 
+    export function getStringComparer(ignoreCase?: boolean) {
+        return ignoreCase ? compareStringsCaseInsensitive : compareStringsCaseSensitive;
+    }
+
     /**
      * Creates a string comparer for use with string collation in the UI.
      */
@@ -2274,7 +2278,7 @@ namespace ts {
         const aComponents = getNormalizedPathComponents(a, currentDirectory);
         const bComponents = getNormalizedPathComponents(b, currentDirectory);
         const sharedLength = Math.min(aComponents.length, bComponents.length);
-        const comparer = ignoreCase ? compareStringsCaseInsensitive : compareStringsCaseSensitive;
+        const comparer = getStringComparer(ignoreCase);
         for (let i = 0; i < sharedLength; i++) {
             const result = comparer(aComponents[i], bComponents[i]);
             if (result !== Comparison.EqualTo) {
@@ -2615,7 +2619,7 @@ namespace ts {
             }
 
             // Sort the offsets array using either the literal or canonical path representations.
-            includeBasePaths.sort(useCaseSensitiveFileNames ? compareStringsCaseSensitive : compareStringsCaseInsensitive);
+            includeBasePaths.sort(getStringComparer(!useCaseSensitiveFileNames));
 
             // Iterate over each include base path and include unique base paths that are not a
             // subpath of an existing base path
diff --git a/src/compiler/sys.ts b/src/compiler/sys.ts
index be95e06eb46..688400fc6d5 100644
--- a/src/compiler/sys.ts
+++ b/src/compiler/sys.ts
@@ -698,7 +698,7 @@ namespace ts {
                         createWatchDirectoryUsing(dynamicPollingWatchFile || createDynamicPriorityPollingWatchFile({ getModifiedTime, setTimeout })) :
                         watchDirectoryUsingFsWatch;
                 const watchDirectoryRecursively = createRecursiveDirectoryWatcher({
-                    filePathComparer: useCaseSensitiveFileNames ? compareStringsCaseSensitive : compareStringsCaseInsensitive,
+                    filePathComparer: getStringComparer(!useCaseSensitiveFileNames),
                     directoryExists,
                     getAccessibleSortedChildDirectories: path => getAccessibleFileSystemEntries(path).directories,
                     watchDirectory,