diff --git a/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates01.errors.txt b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates01.errors.txt
new file mode 100644
index 00000000000..035fbc36c14
--- /dev/null
+++ b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates01.errors.txt
@@ -0,0 +1,39 @@
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates01.ts(21,1): error TS2322: Type '(x: any) => x is B' is not assignable to type '(x: any) => x is A'.
+  Type predicate 'x is B' is not assignable to 'x is A'.
+    Type 'B' is not assignable to type 'A'.
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates01.ts(22,1): error TS2322: Type '(x: any) => x is A' is not assignable to type '(x: any) => x is B'.
+  Type predicate 'x is A' is not assignable to 'x is B'.
+    Type 'A' is not assignable to type 'B'.
+
+
+==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates01.ts (2 errors) ====
+    
+    class A {
+        private a;
+    }
+    
+    class B extends A {
+        private b;
+    }
+    
+    function isA(x: any): x is A {
+        return x instanceof A;
+    }
+    
+    function isB(x: any): x is B {
+        return x instanceof B;
+    }
+    
+    let myIsA = isA;
+    let myIsB = isB;
+    
+    myIsA = myIsB;
+    ~~~~~
+!!! error TS2322: Type '(x: any) => x is B' is not assignable to type '(x: any) => x is A'.
+!!! error TS2322:   Type predicate 'x is B' is not assignable to 'x is A'.
+!!! error TS2322:     Type 'B' is not assignable to type 'A'.
+    myIsB = myIsA;
+    ~~~~~
+!!! error TS2322: Type '(x: any) => x is A' is not assignable to type '(x: any) => x is B'.
+!!! error TS2322:   Type predicate 'x is A' is not assignable to 'x is B'.
+!!! error TS2322:     Type 'A' is not assignable to type 'B'.
\ No newline at end of file
diff --git a/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates01.js b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates01.js
new file mode 100644
index 00000000000..51ea3d9c714
--- /dev/null
+++ b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates01.js
@@ -0,0 +1,65 @@
+//// [assignmentCompatForSignaturesWithTypePredicates01.ts]
+
+class A {
+    private a;
+}
+
+class B extends A {
+    private b;
+}
+
+function isA(x: any): x is A {
+    return x instanceof A;
+}
+
+function isB(x: any): x is B {
+    return x instanceof B;
+}
+
+let myIsA = isA;
+let myIsB = isB;
+
+myIsA = myIsB;
+myIsB = myIsA;
+
+//// [assignmentCompatForSignaturesWithTypePredicates01.js]
+var __extends = (this && this.__extends) || function (d, b) {
+    for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
+    function __() { this.constructor = d; }
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
+};
+var A = (function () {
+    function A() {
+    }
+    return A;
+})();
+var B = (function (_super) {
+    __extends(B, _super);
+    function B() {
+        _super.apply(this, arguments);
+    }
+    return B;
+})(A);
+function isA(x) {
+    return x instanceof A;
+}
+function isB(x) {
+    return x instanceof B;
+}
+var myIsA = isA;
+var myIsB = isB;
+myIsA = myIsB;
+myIsB = myIsA;
+
+
+//// [assignmentCompatForSignaturesWithTypePredicates01.d.ts]
+declare class A {
+    private a;
+}
+declare class B extends A {
+    private b;
+}
+declare function isA(x: any): x is A;
+declare function isB(x: any): x is B;
+declare let myIsA: typeof isA;
+declare let myIsB: typeof isB;
diff --git a/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates02.errors.txt b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates02.errors.txt
new file mode 100644
index 00000000000..8079be20a71
--- /dev/null
+++ b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates02.errors.txt
@@ -0,0 +1,38 @@
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates02.ts(11,25): error TS2304: Cannot find name 'B'.
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates02.ts(17,1): error TS2322: Type '(x: any) => x is any' is not assignable to type '(x: any) => x is A'.
+  Type predicate 'x is any' is not assignable to 'x is A'.
+    Type 'any' is not assignable to type 'A'.
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates02.ts(18,1): error TS2322: Type '(x: any) => x is A' is not assignable to type '(x: any) => x is any'.
+  Type predicate 'x is A' is not assignable to 'x is any'.
+    Type 'A' is not assignable to type 'any'.
+
+
+==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates02.ts (3 errors) ====
+    
+    class A {
+        private a;
+    }
+    
+    function isA(x: any): x is A {
+        return x instanceof A;
+    }
+    
+    function isAny(x: any): x is any {
+        return x instanceof B;
+                            ~
+!!! error TS2304: Cannot find name 'B'.
+    }
+    
+    let myIsA = isA;
+    let myIsAny = isAny;
+    
+    myIsA = myIsAny;
+    ~~~~~
+!!! error TS2322: Type '(x: any) => x is any' is not assignable to type '(x: any) => x is A'.
+!!! error TS2322:   Type predicate 'x is any' is not assignable to 'x is A'.
+!!! error TS2322:     Type 'any' is not assignable to type 'A'.
+    myIsAny = myIsA;
+    ~~~~~~~
+!!! error TS2322: Type '(x: any) => x is A' is not assignable to type '(x: any) => x is any'.
+!!! error TS2322:   Type predicate 'x is A' is not assignable to 'x is any'.
+!!! error TS2322:     Type 'A' is not assignable to type 'any'.
\ No newline at end of file
diff --git a/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates02.js b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates02.js
new file mode 100644
index 00000000000..cdd7fbe0f96
--- /dev/null
+++ b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates02.js
@@ -0,0 +1,46 @@
+//// [assignmentCompatForSignaturesWithTypePredicates02.ts]
+
+class A {
+    private a;
+}
+
+function isA(x: any): x is A {
+    return x instanceof A;
+}
+
+function isAny(x: any): x is any {
+    return x instanceof B;
+}
+
+let myIsA = isA;
+let myIsAny = isAny;
+
+myIsA = myIsAny;
+myIsAny = myIsA;
+
+//// [assignmentCompatForSignaturesWithTypePredicates02.js]
+var A = (function () {
+    function A() {
+    }
+    return A;
+})();
+function isA(x) {
+    return x instanceof A;
+}
+function isAny(x) {
+    return x instanceof B;
+}
+var myIsA = isA;
+var myIsAny = isAny;
+myIsA = myIsAny;
+myIsAny = myIsA;
+
+
+//// [assignmentCompatForSignaturesWithTypePredicates02.d.ts]
+declare class A {
+    private a;
+}
+declare function isA(x: any): x is A;
+declare function isAny(x: any): x is any;
+declare let myIsA: typeof isA;
+declare let myIsAny: typeof isAny;
diff --git a/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates03.errors.txt b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates03.errors.txt
new file mode 100644
index 00000000000..bfb94ff40d5
--- /dev/null
+++ b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates03.errors.txt
@@ -0,0 +1,38 @@
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates03.ts(20,1): error TS2322: Type '(x: any) => x is B' is not assignable to type '(x: any) => x is A'.
+  Type predicate 'x is B' is not assignable to 'x is A'.
+    Type 'B' is not assignable to type 'A'.
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates03.ts(21,1): error TS2322: Type '(x: any) => x is A' is not assignable to type '(x: any) => x is B'.
+  Type predicate 'x is A' is not assignable to 'x is B'.
+    Type 'A' is not assignable to type 'B'.
+
+
+==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates03.ts (2 errors) ====
+    
+    interface A {
+        a?;
+    }
+    
+    interface B {
+    }
+    
+    function isA(x: any): x is A {
+        return !!(<A>x).a;
+    }
+    
+    function isB(x: any): x is B {
+        return !!isA(x);
+    }
+    
+    let myIsA = isA;
+    let myIsAny = isB;
+    
+    myIsA = myIsAny;
+    ~~~~~
+!!! error TS2322: Type '(x: any) => x is B' is not assignable to type '(x: any) => x is A'.
+!!! error TS2322:   Type predicate 'x is B' is not assignable to 'x is A'.
+!!! error TS2322:     Type 'B' is not assignable to type 'A'.
+    myIsAny = myIsA;
+    ~~~~~~~
+!!! error TS2322: Type '(x: any) => x is A' is not assignable to type '(x: any) => x is B'.
+!!! error TS2322:   Type predicate 'x is A' is not assignable to 'x is B'.
+!!! error TS2322:     Type 'A' is not assignable to type 'B'.
\ No newline at end of file
diff --git a/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates03.js b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates03.js
new file mode 100644
index 00000000000..10f9ce61e95
--- /dev/null
+++ b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates03.js
@@ -0,0 +1,46 @@
+//// [assignmentCompatForSignaturesWithTypePredicates03.ts]
+
+interface A {
+    a?;
+}
+
+interface B {
+}
+
+function isA(x: any): x is A {
+    return !!(<A>x).a;
+}
+
+function isB(x: any): x is B {
+    return !!isA(x);
+}
+
+let myIsA = isA;
+let myIsAny = isB;
+
+myIsA = myIsAny;
+myIsAny = myIsA;
+
+//// [assignmentCompatForSignaturesWithTypePredicates03.js]
+function isA(x) {
+    return !!x.a;
+}
+function isB(x) {
+    return !!isA(x);
+}
+var myIsA = isA;
+var myIsAny = isB;
+myIsA = myIsAny;
+myIsAny = myIsA;
+
+
+//// [assignmentCompatForSignaturesWithTypePredicates03.d.ts]
+interface A {
+    a?: any;
+}
+interface B {
+}
+declare function isA(x: any): x is A;
+declare function isB(x: any): x is B;
+declare let myIsA: typeof isA;
+declare let myIsAny: typeof isB;
diff --git a/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates04.errors.txt b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates04.errors.txt
new file mode 100644
index 00000000000..16abe2efeaf
--- /dev/null
+++ b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates04.errors.txt
@@ -0,0 +1,43 @@
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates04.ts(25,1): error TS2322: Type '(x: any) => x is E' is not assignable to type '(x: any) => x is number'.
+  Type predicate 'x is E' is not assignable to 'x is number'.
+    Type 'E' is not assignable to type 'number'.
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates04.ts(26,1): error TS2322: Type '(x: any) => x is number' is not assignable to type '(x: any) => x is E'.
+  Type predicate 'x is number' is not assignable to 'x is E'.
+    Type 'number' is not assignable to type 'E'.
+
+
+==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatForSignaturesWithTypePredicates04.ts (2 errors) ====
+    
+    enum E {
+        A = 1,
+        B = 2,
+        C = 3,
+    }
+    
+    function isA(x: any): x is number {
+        return typeof x === "number";
+    }
+    
+    function isB(x: any): x is E {
+        switch (x) {
+            case E.A:
+            case E.B:
+            case E.C:
+                return true;
+        }
+        return false;
+    }
+    
+    let myIsA = isA;
+    let myIsB = isB;
+    
+    myIsA = myIsB;
+    ~~~~~
+!!! error TS2322: Type '(x: any) => x is E' is not assignable to type '(x: any) => x is number'.
+!!! error TS2322:   Type predicate 'x is E' is not assignable to 'x is number'.
+!!! error TS2322:     Type 'E' is not assignable to type 'number'.
+    myIsB = myIsA;
+    ~~~~~
+!!! error TS2322: Type '(x: any) => x is number' is not assignable to type '(x: any) => x is E'.
+!!! error TS2322:   Type predicate 'x is number' is not assignable to 'x is E'.
+!!! error TS2322:     Type 'number' is not assignable to type 'E'.
\ No newline at end of file
diff --git a/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates04.js b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates04.js
new file mode 100644
index 00000000000..dfb70f2ee56
--- /dev/null
+++ b/tests/baselines/reference/assignmentCompatForSignaturesWithTypePredicates04.js
@@ -0,0 +1,63 @@
+//// [assignmentCompatForSignaturesWithTypePredicates04.ts]
+
+enum E {
+    A = 1,
+    B = 2,
+    C = 3,
+}
+
+function isA(x: any): x is number {
+    return typeof x === "number";
+}
+
+function isB(x: any): x is E {
+    switch (x) {
+        case E.A:
+        case E.B:
+        case E.C:
+            return true;
+    }
+    return false;
+}
+
+let myIsA = isA;
+let myIsB = isB;
+
+myIsA = myIsB;
+myIsB = myIsA;
+
+//// [assignmentCompatForSignaturesWithTypePredicates04.js]
+var E;
+(function (E) {
+    E[E["A"] = 1] = "A";
+    E[E["B"] = 2] = "B";
+    E[E["C"] = 3] = "C";
+})(E || (E = {}));
+function isA(x) {
+    return typeof x === "number";
+}
+function isB(x) {
+    switch (x) {
+        case E.A:
+        case E.B:
+        case E.C:
+            return true;
+    }
+    return false;
+}
+var myIsA = isA;
+var myIsB = isB;
+myIsA = myIsB;
+myIsB = myIsA;
+
+
+//// [assignmentCompatForSignaturesWithTypePredicates04.d.ts]
+declare enum E {
+    A = 1,
+    B = 2,
+    C = 3,
+}
+declare function isA(x: any): x is number;
+declare function isB(x: any): x is E;
+declare let myIsA: typeof isA;
+declare let myIsB: typeof isB;