diff --git a/src/harness/fourslash.ts b/src/harness/fourslash.ts
index fb3bed30c3b..144cc9745d9 100644
--- a/src/harness/fourslash.ts
+++ b/src/harness/fourslash.ts
@@ -2241,11 +2241,12 @@ module FourSlash {
             (fn, contents) => result = contents,
             ts.ScriptTarget.Latest,
             sys.useCaseSensitiveFileNames);
-        var program = ts.createProgram([Harness.Compiler.fourslashFilename, fileName], { out: "fourslashTestOutput.js" }, host);
+        // TODO (drosen): We need to enforce checking on these tests.
+        var program = ts.createProgram([Harness.Compiler.fourslashFilename, fileName], { out: "fourslashTestOutput.js", noResolve: true }, host);
         var checker = ts.createTypeChecker(program, /*fullTypeCheckMode*/ true);
         checker.checkProgram();
 
-        var errs = checker.getDiagnostics(program.getSourceFile(fileName));
+        var errs = program.getDiagnostics().concat(checker.getDiagnostics());
         if (errs.length > 0) {
             throw new Error('Error compiling ' + fileName + ': ' + errs.map(e => e.messageText).join('\r\n'));
         }
diff --git a/src/harness/harness.ts b/src/harness/harness.ts
index d5eaa3828a1..aee0ef3c534 100644
--- a/src/harness/harness.ts
+++ b/src/harness/harness.ts
@@ -585,7 +585,7 @@ module Harness {
                             return defaultLibSourceFile;
                         }
                         // Don't throw here -- the compiler might be looking for a test that actually doesn't exist as part of the TC
-                        return null;
+                        return undefined;
                     }
                 },
                 getDefaultLibFilename: () => defaultLibFileName,
diff --git a/tests/cases/fourslash/completionListInTemplateLiteralParts1.ts b/tests/cases/fourslash/completionListInTemplateLiteralParts1.ts
index a71584bdbdd..0166546f63e 100644
--- a/tests/cases/fourslash/completionListInTemplateLiteralParts1.ts
+++ b/tests/cases/fourslash/completionListInTemplateLiteralParts1.ts
@@ -8,4 +8,4 @@ test.markers().forEach(marker => {
     goTo.position(marker.position);
 
     verify.completionListItemsCountIsGreaterThan(0)
-}}
\ No newline at end of file
+});
\ No newline at end of file
diff --git a/tests/cases/fourslash/completionListInTemplateLiteralPartsNegatives1.ts b/tests/cases/fourslash/completionListInTemplateLiteralPartsNegatives1.ts
index 1624192057b..ac64a41fb56 100644
--- a/tests/cases/fourslash/completionListInTemplateLiteralPartsNegatives1.ts
+++ b/tests/cases/fourslash/completionListInTemplateLiteralPartsNegatives1.ts
@@ -8,4 +8,4 @@ test.markers().forEach(marker => {
     goTo.position(marker.position);
 
     verify.completionListIsEmpty()
-}
\ No newline at end of file
+});
\ No newline at end of file
diff --git a/tests/cases/fourslash/findAllRefsInsideTemplates1.ts b/tests/cases/fourslash/findAllRefsInsideTemplates1.ts
index e4501219265..dd4461751de 100644
--- a/tests/cases/fourslash/findAllRefsInsideTemplates1.ts
+++ b/tests/cases/fourslash/findAllRefsInsideTemplates1.ts
@@ -8,5 +8,5 @@ test.ranges().forEach(targetRange => {
 
     test.ranges().forEach(range => {
         verify.referencesAtPositionContains(range);
-    }
-}
\ No newline at end of file
+    });
+});
\ No newline at end of file
diff --git a/tests/cases/fourslash/findAllRefsInsideTemplates2.ts b/tests/cases/fourslash/findAllRefsInsideTemplates2.ts
index cafddd4f45b..7f585234082 100644
--- a/tests/cases/fourslash/findAllRefsInsideTemplates2.ts
+++ b/tests/cases/fourslash/findAllRefsInsideTemplates2.ts
@@ -8,5 +8,5 @@ test.ranges().forEach(targetRange => {
 
     test.ranges().forEach(range => {
         verify.referencesAtPositionContains(range);
-    }
-}
\ No newline at end of file
+    });
+});
\ No newline at end of file
diff --git a/tests/cases/fourslash/getOccurrencesReturnBroken.ts b/tests/cases/fourslash/getOccurrencesReturnBroken.ts
index e740e7f2bb3..08ec794f7e8 100644
--- a/tests/cases/fourslash/getOccurrencesReturnBroken.ts
+++ b/tests/cases/fourslash/getOccurrencesReturnBroken.ts
@@ -51,4 +51,4 @@ for (var i = 1; i <= test.markers().length; i++) {
             verify.occurrencesAtPositionCount(1); // 'return' is an instance member
             break;
     }
-});
\ No newline at end of file
+}
\ No newline at end of file