diff --git a/src/harness/fourslash.ts b/src/harness/fourslash.ts
index 3987fdb6ffa..e0b74318e26 100644
--- a/src/harness/fourslash.ts
+++ b/src/harness/fourslash.ts
@@ -237,9 +237,6 @@ module FourSlash {
             getLength: () => {
                 return sourceText.length;
             },
-            getLineStartPositions: () => {
-                return <number[]>[];
-            },
             getChangeRange: (oldSnapshot: ts.IScriptSnapshot) => {
                 return <ts.TextChangeRange>undefined;
             }
diff --git a/src/harness/harnessLanguageService.ts b/src/harness/harnessLanguageService.ts
index 4d7572d9f30..1d442822866 100644
--- a/src/harness/harnessLanguageService.ts
+++ b/src/harness/harnessLanguageService.ts
@@ -72,14 +72,6 @@ module Harness.LanguageService {
             return this.textSnapshot.length;
         }
 
-        public getLineStartPositions(): string {
-            if (this.lineMap === null) {
-                this.lineMap = ts.computeLineStarts(this.textSnapshot);
-            }
-
-            return JSON.stringify(this.lineMap);
-        }
-
         public getChangeRange(oldScript: ts.ScriptSnapshotShim): string {
             var oldShim = <ScriptSnapshotShim>oldScript;
             var range = this.scriptInfo.getTextChangeRangeBetweenVersions(oldShim.version, this.version);
diff --git a/src/services/services.ts b/src/services/services.ts
index c8b947161b2..c188ff84a22 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -74,13 +74,6 @@ module ts {
         /** Gets the length of this script snapshot. */
         getLength(): number;
 
-        /**
-         * This call returns the array containing the start position of every line.  
-         * i.e."[0, 10, 55]".  TODO: consider making this optional.  The language service could
-         * always determine this (albeit in a more expensive manner).
-         */
-        getLineStartPositions(): number[];
-
         /**
          * Gets the TextChangeRange that describe how the text changed between this text and 
          * an older version.  This information is used by the incremental parser to determine
@@ -106,14 +99,6 @@ module ts {
                 return this.text.length;
             }
 
-            public getLineStartPositions(): number[] {
-                if (!this._lineStartPositions) {
-                    this._lineStartPositions = computeLineStarts(this.text);
-                }
-
-                return this._lineStartPositions;
-            }
-
             public getChangeRange(oldSnapshot: IScriptSnapshot): TextChangeRange {
                 // Text-based snapshots do not support incremental parsing. Return undefined
                 // to signal that to the caller.
diff --git a/src/services/shims.ts b/src/services/shims.ts
index 9e042c05a93..c9f33914e09 100644
--- a/src/services/shims.ts
+++ b/src/services/shims.ts
@@ -25,9 +25,6 @@ module ts {
         /** Gets the length of this script snapshot. */
         getLength(): number;
 
-        /** This call returns the JSON-encoded array of the type: number[] */
-        getLineStartPositions(): string;
-
         /**
          * Returns a JSON-encoded value of the type:
          *   { span: { start: number; length: number }; newLength: number }
@@ -192,14 +189,6 @@ module ts {
             return this.scriptSnapshotShim.getLength();
         }
 
-        public getLineStartPositions(): number[] {
-            if (this.lineStartPositions == null) {
-                this.lineStartPositions = JSON.parse(this.scriptSnapshotShim.getLineStartPositions());
-            }
-
-            return this.lineStartPositions;
-        }
-
         public getChangeRange(oldSnapshot: IScriptSnapshot): TextChangeRange {
             var oldSnapshotShim = <ScriptSnapshotShimAdapter>oldSnapshot;
             var encoded = this.scriptSnapshotShim.getChangeRange(oldSnapshotShim.scriptSnapshotShim);