diff --git a/src/harness/fourslash.ts b/src/harness/fourslash.ts
index 1e499fd79be..a97319ff332 100644
--- a/src/harness/fourslash.ts
+++ b/src/harness/fourslash.ts
@@ -959,10 +959,9 @@ module FourSlash {
             var help = this.languageService.getSignatureHelpItems(this.activeFile.fileName, this.currentCaretPosition);
 
             var item = help.items[help.selectedItemIndex];
-            var state = this.languageService.getSignatureHelpCurrentArgumentState(this.activeFile.fileName, this.currentCaretPosition, help.applicableSpan.start());
-
+ 
             // Same logic as in getActiveSignatureHelp - this value might be -1 until a parameter value actually gets typed
-            var currentParam = state === undefined ? 0 : state.argumentIndex;
+            var currentParam = help.argumentIndex < 0 ? 0 : help.argumentIndex;
             return item.parameters[currentParam];
         }
 
diff --git a/src/services/services.ts b/src/services/services.ts
index 7d11d9ab32d..611520f8c32 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -651,16 +651,18 @@ module ts {
         getCompletionsAtPosition(fileName: string, position: number, isMemberCompletion: boolean): CompletionInfo;
         getCompletionEntryDetails(fileName: string, position: number, entryName: string): CompletionEntryDetails;
 
-        getTypeAtPosition(fileName: string, position: number): TypeInfo;
         getQuickInfoAtPosition(fileName: string, position: number): QuickInfo;
 
+        // Obsolete.  Use getQuickInfoAtPosition instead.
+        getTypeAtPosition(fileName: string, position: number): TypeInfo;
+
         getNameOrDottedNameSpan(fileName: string, startPos: number, endPos: number): TypeScript.TextSpan;
 
         getBreakpointStatementAtPosition(fileName: string, position: number): TypeScript.TextSpan;
 
         getSignatureHelpItems(fileName: string, position: number): SignatureHelpItems;
-        getSignatureHelpCurrentArgumentState(fileName: string, position: number, applicableSpanStart: number): SignatureHelpState;
 
+        // Obsolete.  Use getSignatureHelpItems instead.
         getSignatureAtPosition(fileName: string, position: number): SignatureInfo;
 
         getRenameInfo(fileName: string, position: number): RenameInfo;
@@ -861,9 +863,6 @@ module ts {
         items: SignatureHelpItem[];
         applicableSpan: TypeScript.TextSpan;
         selectedItemIndex: number;
-    }
-
-    export interface SignatureHelpState {
         argumentIndex: number;
         argumentCount: number;
     }
@@ -3765,16 +3764,6 @@ module ts {
             return SignatureHelp.getSignatureHelpItems(sourceFile, position, typeInfoResolver, cancellationToken);
         }
 
-        /**
-         * This is a syntactic operation
-         */
-        function getSignatureHelpCurrentArgumentState(fileName: string, position: number, applicableSpanStart: number): SignatureHelpState {
-            fileName = TypeScript.switchToForwardSlashes(fileName);
-            var sourceFile = getCurrentSourceFile(fileName);
-
-            return SignatureHelp.getSignatureHelpCurrentArgumentState(sourceFile, position, applicableSpanStart);
-        }
-
         function getSignatureAtPosition(filename: string, position: number): SignatureInfo {
             var signatureHelpItems = getSignatureHelpItems(filename, position);
 
@@ -3782,7 +3771,7 @@ module ts {
                 return undefined;
             }
 
-            var currentArguemntState = getSignatureHelpCurrentArgumentState(filename, position, signatureHelpItems.applicableSpan.start());
+            var currentArgumentState = { argumentIndex: signatureHelpItems.argumentIndex, argumentCount: signatureHelpItems.argumentCount };
 
             var formalSignatures: FormalSignatureItemInfo[] = [];
             forEach(signatureHelpItems.items, signature => {
@@ -3827,7 +3816,7 @@ module ts {
                 parameterMinChar: signatureHelpItems.applicableSpan.start(),
                 parameterLimChar: signatureHelpItems.applicableSpan.end(),
                 currentParameterIsTypeParameter: false,
-                currentParameter: currentArguemntState.argumentIndex
+                currentParameter: currentArgumentState.argumentIndex
             };
 
             return {
@@ -4465,7 +4454,6 @@ module ts {
             getCompletionEntryDetails: getCompletionEntryDetails,
             getTypeAtPosition: getTypeAtPosition,
             getSignatureHelpItems: getSignatureHelpItems,
-            getSignatureHelpCurrentArgumentState: getSignatureHelpCurrentArgumentState,
             getQuickInfoAtPosition: getQuickInfoAtPosition,
             getDefinitionAtPosition: getDefinitionAtPosition,
             getReferencesAtPosition: getReferencesAtPosition,
diff --git a/src/services/shims.ts b/src/services/shims.ts
index 2757330503a..45ac958935e 100644
--- a/src/services/shims.ts
+++ b/src/services/shims.ts
@@ -84,14 +84,16 @@ module ts {
         getCompletionEntryDetails(fileName: string, position: number, entryName: string): string;
 
         getQuickInfoAtPosition(fileName: string, position: number): string;
+
+        // Obsolete.  Use getQuickInfoAtPosition instead.
         getTypeAtPosition(fileName: string, position: number): string;
 
         getNameOrDottedNameSpan(fileName: string, startPos: number, endPos: number): string;
         getBreakpointStatementAtPosition(fileName: string, position: number): string;
 
         getSignatureHelpItems(fileName: string, position: number): string;
-        getSignatureHelpCurrentArgumentState(fileName: string, position: number, applicableSpanStart: number): string;
 
+        // Obsolete.  Use getSignatureHelpItems instead.
         getSignatureAtPosition(fileName: string, position: number): string;
 
         /**
@@ -623,15 +625,6 @@ module ts {
                 });
         }
 
-        public getSignatureHelpCurrentArgumentState(fileName: string, position: number, applicableSpanStart: number): string {
-            return this.forwardJSONCall(
-                "getSignatureHelpCurrentArgumentState('" + fileName + "', " + position + ", " + applicableSpanStart + ")",
-                () => {
-                    var signatureHelpState = this.languageService.getSignatureHelpCurrentArgumentState(fileName, position, applicableSpanStart);
-                    return signatureHelpState;
-                });
-        }
-
         public getSignatureAtPosition(fileName: string, position: number): string {
             return this.forwardJSONCall(
                 "getSignatureAtPosition('" + fileName + "', " + position + ")",
diff --git a/src/services/signatureHelp.ts b/src/services/signatureHelp.ts
index 4a02c99204d..796472c030e 100644
--- a/src/services/signatureHelp.ts
+++ b/src/services/signatureHelp.ts
@@ -337,15 +337,19 @@ module ts.SignatureHelp {
             var applicableSpanStart = argumentListOrTypeArgumentList.getFullStart();
             var applicableSpanEnd = skipTrivia(sourceFile.text, argumentListOrTypeArgumentList.end, /*stopAfterLineBreak*/ false);
             var applicableSpan = new TypeScript.TextSpan(applicableSpanStart, applicableSpanEnd - applicableSpanStart);
+
+            var state = getSignatureHelpCurrentArgumentState(sourceFile, position, applicableSpanStart);
             return {
                 items: items,
                 applicableSpan: applicableSpan,
-                selectedItemIndex: selectedItemIndex
+                selectedItemIndex: selectedItemIndex,
+                argumentIndex: state.argumentIndex,
+                argumentCount: state.argumentCount
             };
         }
     }
 
-    export function getSignatureHelpCurrentArgumentState(sourceFile: SourceFile, position: number, applicableSpanStart: number): SignatureHelpState {
+    function getSignatureHelpCurrentArgumentState(sourceFile: SourceFile, position: number, applicableSpanStart: number): { argumentIndex: number; argumentCount: number } {
         var tokenPrecedingSpanStart = findPrecedingToken(applicableSpanStart, sourceFile);
         if (!tokenPrecedingSpanStart) {
             return undefined;