diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index ba5cdf044f3..ead84957731 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -403,6 +403,8 @@ module ts {
         templateSpans: NodeArray<TemplateSpan>;
     }
 
+    // Each of these corresponds to a substitution expression and a template literal, in that order.
+    // The template literal must have kind TemplateMiddleLiteral or TemplateTailLiteral.
     export interface TemplateSpan extends Node {
         expression: Expression;
         literal: LiteralExpression;
@@ -440,8 +442,7 @@ module ts {
 
     export interface TaggedTemplateExpression extends Expression {
         tag: Expression;
-        // Either a LiteralExpression of kind NoSubstitutionTemplateLiteral, or a TemplateExpression
-        template: Expression;
+        template: LiteralExpression | TemplateExpression;
     }
 
     export interface TypeAssertion extends Expression {
diff --git a/src/services/services.ts b/src/services/services.ts
index 9b48900f933..d208eb87e96 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -2471,12 +2471,12 @@ module ts {
             }
 
             function isCompletionListBlocker(previousToken: Node): boolean {
-                return isInStringOrRegularExpressionLiteral(previousToken) ||
+                return isInStringOrRegularExpressionOrTemplateLiteral(previousToken) ||
                     isIdentifierDefinitionLocation(previousToken) ||
                     isRightOfIllegalDot(previousToken);
             }
 
-            function isInStringOrRegularExpressionLiteral(previousToken: Node): boolean {
+            function isInStringOrRegularExpressionOrTemplateLiteral(previousToken: Node): boolean {
                 if (previousToken.kind === SyntaxKind.StringLiteral || isTemplateLiteralKind(previousToken.kind)) {
                     // The position has to be either: 1. entirely within the token text, or 
                     // 2. at the end position, and the string literal is not terminated