diff --git a/src/server/session.ts b/src/server/session.ts
index 5873958d613..3eea095d9d5 100644
--- a/src/server/session.ts
+++ b/src/server/session.ts
@@ -235,7 +235,7 @@ namespace ts.server {
         }
 
         updateErrorCheck(checkList: PendingErrorCheck[], seq: number,
-            matchSeq: (seq: number) => boolean, ms = 1500, followMs = 200) {
+            matchSeq: (seq: number) => boolean, ms = 1500, followMs = 200, requireOpen = true) {
             if (followMs > ms) {
                 followMs = ms;
             }
@@ -250,7 +250,7 @@ namespace ts.server {
             var checkOne = () => {
                 if (matchSeq(seq)) {
                     var checkSpec = checkList[index++];
-                    if (checkSpec.project.getSourceFileFromName(checkSpec.fileName, true)) {
+                    if (checkSpec.project.getSourceFileFromName(checkSpec.fileName, requireOpen)) {
                         this.syntacticCheck(checkSpec.fileName, checkSpec.project);
                         this.immediateId = setImmediate(() => {
                             this.semanticCheck(checkSpec.fileName, checkSpec.project);
@@ -872,7 +872,7 @@ namespace ts.server {
                     let normalizedFileName = ts.normalizePath(fileName);
                     return { fileName: normalizedFileName, project };
                 });
-                this.updateErrorCheck(checkList, this.changeSeq, (n) => n == this.changeSeq, delay);
+                this.updateErrorCheck(checkList, this.changeSeq, (n) => n == this.changeSeq, delay, 200, false);
             }
         }