diff --git a/tests/baselines/reference/typeGuardsWithInstanceOfByConstructorSignature.errors.txt b/tests/baselines/reference/typeGuardsWithInstanceOfByConstructorSignature.errors.txt
index be1a0e5a2c3..4960940d3ab 100644
--- a/tests/baselines/reference/typeGuardsWithInstanceOfByConstructorSignature.errors.txt
+++ b/tests/baselines/reference/typeGuardsWithInstanceOfByConstructorSignature.errors.txt
@@ -1,15 +1,15 @@
 tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(12,10): error TS2339: Property 'bar' does not exist on type 'A'.
 tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(33,5): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(34,10): error TS2339: Property 'bar' does not exist on type 'B<number>'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(62,10): error TS2339: Property 'bar1' does not exist on type 'C1 | C2'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(63,10): error TS2339: Property 'bar2' does not exist on type 'C1 | C2'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(82,10): error TS2339: Property 'bar' does not exist on type 'D'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(108,10): error TS2339: Property 'bar1' does not exist on type 'E1 | E2'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(109,10): error TS2339: Property 'bar2' does not exist on type 'E1 | E2'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(131,11): error TS2339: Property 'foo' does not exist on type 'string | F'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(132,11): error TS2339: Property 'bar' does not exist on type 'string | F'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(157,11): error TS2339: Property 'foo2' does not exist on type 'G1'.
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(179,11): error TS2339: Property 'bar' does not exist on type 'H'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(65,10): error TS2339: Property 'bar1' does not exist on type 'C1 | C2'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(66,10): error TS2339: Property 'bar2' does not exist on type 'C1 | C2'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(85,10): error TS2339: Property 'bar' does not exist on type 'D'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(111,10): error TS2339: Property 'bar1' does not exist on type 'E1 | E2'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(112,10): error TS2339: Property 'bar2' does not exist on type 'E1 | E2'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(134,11): error TS2339: Property 'foo' does not exist on type 'string | F'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(135,11): error TS2339: Property 'bar' does not exist on type 'string | F'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(160,11): error TS2339: Property 'foo2' does not exist on type 'G1'.
+tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts(182,11): error TS2339: Property 'bar' does not exist on type 'H'.
 
 
 ==== tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts (12 errors) ====
@@ -69,17 +69,20 @@ tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstru
     }
     interface C1 {
         foo: string;
+        c: string;
         bar1: number;
     }
     interface C2 {
         foo: string;
+        c: string;
         bar2: number;
     }
     declare var C: CConstructor;
     
     var obj5: C1 | A;
-    if (obj5 instanceof C) { // narrowed to C1.
+    if (obj5 instanceof C) { // narrowed to C1|C2.
         obj5.foo;
+        obj5.c;
         obj5.bar1;
              ~~~~
 !!! error TS2339: Property 'bar1' does not exist on type 'C1 | C2'.
@@ -130,7 +133,7 @@ tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstru
     declare var E: EConstructor;
     
     var obj9: E1 | A;
-    if (obj9 instanceof E) { // narrowed to E1.
+    if (obj9 instanceof E) { // narrowed to E1 | E2
         obj9.foo;
         obj9.bar1;
              ~~~~
diff --git a/tests/baselines/reference/typeGuardsWithInstanceOfByConstructorSignature.js b/tests/baselines/reference/typeGuardsWithInstanceOfByConstructorSignature.js
index e5b12bacb1f..7e6b3324470 100644
--- a/tests/baselines/reference/typeGuardsWithInstanceOfByConstructorSignature.js
+++ b/tests/baselines/reference/typeGuardsWithInstanceOfByConstructorSignature.js
@@ -49,17 +49,20 @@ interface CConstructor {
 }
 interface C1 {
     foo: string;
+    c: string;
     bar1: number;
 }
 interface C2 {
     foo: string;
+    c: string;
     bar2: number;
 }
 declare var C: CConstructor;
 
 var obj5: C1 | A;
-if (obj5 instanceof C) { // narrowed to C1.
+if (obj5 instanceof C) { // narrowed to C1|C2.
     obj5.foo;
+    obj5.c;
     obj5.bar1;
     obj5.bar2;
 }
@@ -104,7 +107,7 @@ interface E2 {
 declare var E: EConstructor;
 
 var obj9: E1 | A;
-if (obj9 instanceof E) { // narrowed to E1.
+if (obj9 instanceof E) { // narrowed to E1 | E2
     obj9.foo;
     obj9.bar1;
     obj9.bar2;
@@ -213,6 +216,7 @@ if (obj4 instanceof B) {
 var obj5;
 if (obj5 instanceof C) {
     obj5.foo;
+    obj5.c;
     obj5.bar1;
     obj5.bar2;
 }
diff --git a/tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts b/tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts
index fee92ff10ca..b81dd26652b 100644
--- a/tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts
+++ b/tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOfByConstructorSignature.ts
@@ -48,17 +48,20 @@ interface CConstructor {
 }
 interface C1 {
     foo: string;
+    c: string;
     bar1: number;
 }
 interface C2 {
     foo: string;
+    c: string;
     bar2: number;
 }
 declare var C: CConstructor;
 
 var obj5: C1 | A;
-if (obj5 instanceof C) { // narrowed to C1.
+if (obj5 instanceof C) { // narrowed to C1|C2.
     obj5.foo;
+    obj5.c;
     obj5.bar1;
     obj5.bar2;
 }
@@ -103,7 +106,7 @@ interface E2 {
 declare var E: EConstructor;
 
 var obj9: E1 | A;
-if (obj9 instanceof E) { // narrowed to E1.
+if (obj9 instanceof E) { // narrowed to E1 | E2
     obj9.foo;
     obj9.bar1;
     obj9.bar2;