diff --git a/src/server/session.ts b/src/server/session.ts
index 80831e692844f..a58b47f566fb3 100644
--- a/src/server/session.ts
+++ b/src/server/session.ts
@@ -495,6 +495,9 @@ module ts.server {
                                 if (lineText.charAt(i) == " ") {
                                     indentPosition--;
                                 }
+                                else if (lineText.charAt(i) == "\t") {
+                                    indentPosition -= editorOptions.IndentSize;
+                                }
                                 else {
                                     break;
                                 }