diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index f175b6806551b..8d060bae71b75 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -2838,7 +2838,23 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             }
             else if (isClassLike(declaration)) {
                 // still might be illegal if the usage is within a computed property name in the class (eg class A { static p = "a"; [A.p]() {} })
-                return !findAncestor(usage, n => isComputedPropertyName(n) && n.parent.parent === declaration);
+                // or when used within a decorator in the class (e.g. `@dec(A.x) class A { static x = "x" }`),
+                // except when used in a function that is not an IIFE (e.g., `@dec(() => A.x) class A { ... }`)
+                const container = findAncestor(usage, n =>
+                    n === declaration ? "quit" :
+                        isComputedPropertyName(n) ? n.parent.parent === declaration :
+                        isDecorator(n) && (n.parent === declaration ||
+                            isMethodDeclaration(n.parent) && n.parent.parent === declaration ||
+                            isGetOrSetAccessorDeclaration(n.parent) && n.parent.parent === declaration ||
+                            isPropertyDeclaration(n.parent) && n.parent.parent === declaration ||
+                            isParameter(n.parent) && n.parent.parent.parent === declaration));
+                if (!container) {
+                    return true;
+                }
+                if (isDecorator(container)) {
+                    return !!findAncestor(usage, n => n === container ? "quit" : isFunctionLike(n) && !getImmediatelyInvokedFunctionExpression(n));
+                }
+                return false;
             }
             else if (isPropertyDeclaration(declaration)) {
                 // still might be illegal if a self-referencing property initializer (eg private x = this.x)
diff --git a/tests/baselines/reference/decoratorReferences.js b/tests/baselines/reference/decoratorReferences.js
index dbf57c8a8f8a7..124a469f2986f 100644
--- a/tests/baselines/reference/decoratorReferences.js
+++ b/tests/baselines/reference/decoratorReferences.js
@@ -3,7 +3,7 @@
 //// [decoratorReferences.ts]
 declare function y(...args: any[]): any;
 type T = number;
-@y(1 as T, C) // <-- T should be resolved to the type alias, not the type parameter of the class; C should resolve to the class
+@y(1 as T, () => C) // <-- T should be resolved to the type alias, not the type parameter of the class; C should resolve to the class
 class C<T> {
     @y(null as T) // <-- y should resolve to the function declaration, not the parameter; T should resolve to the type parameter of the class
     method(@y x, y) {} // <-- decorator y should be resolved at the class declaration, not the parameter.
@@ -29,7 +29,7 @@ var C = /** @class */ (function () {
         __param(0, y)
     ], C.prototype, "method", null);
     C = __decorate([
-        y(1, C) // <-- T should be resolved to the type alias, not the type parameter of the class; C should resolve to the class
+        y(1, function () { return C; }) // <-- T should be resolved to the type alias, not the type parameter of the class; C should resolve to the class
     ], C);
     return C;
 }());
diff --git a/tests/baselines/reference/decoratorReferences.symbols b/tests/baselines/reference/decoratorReferences.symbols
index 96ef42ed96958..f5b4cc20364fa 100644
--- a/tests/baselines/reference/decoratorReferences.symbols
+++ b/tests/baselines/reference/decoratorReferences.symbols
@@ -8,7 +8,7 @@ declare function y(...args: any[]): any;
 type T = number;
 >T : Symbol(T, Decl(decoratorReferences.ts, 0, 40))
 
-@y(1 as T, C) // <-- T should be resolved to the type alias, not the type parameter of the class; C should resolve to the class
+@y(1 as T, () => C) // <-- T should be resolved to the type alias, not the type parameter of the class; C should resolve to the class
 >y : Symbol(y, Decl(decoratorReferences.ts, 0, 0))
 >T : Symbol(T, Decl(decoratorReferences.ts, 0, 40))
 >C : Symbol(C, Decl(decoratorReferences.ts, 1, 16))
diff --git a/tests/baselines/reference/decoratorReferences.types b/tests/baselines/reference/decoratorReferences.types
index c5818a72535bd..c0ab3b286de15 100644
--- a/tests/baselines/reference/decoratorReferences.types
+++ b/tests/baselines/reference/decoratorReferences.types
@@ -8,11 +8,12 @@ declare function y(...args: any[]): any;
 type T = number;
 >T : number
 
-@y(1 as T, C) // <-- T should be resolved to the type alias, not the type parameter of the class; C should resolve to the class
->y(1 as T, C) : any
+@y(1 as T, () => C) // <-- T should be resolved to the type alias, not the type parameter of the class; C should resolve to the class
+>y(1 as T, () => C) : any
 >y : (...args: any[]) => any
 >1 as T : number
 >1 : 1
+>() => C : () => typeof C
 >C : typeof C
 
 class C<T> {
diff --git a/tests/baselines/reference/useBeforeDeclaration_classDecorators.1.errors.txt b/tests/baselines/reference/useBeforeDeclaration_classDecorators.1.errors.txt
new file mode 100644
index 0000000000000..ec820f5b8a1c4
--- /dev/null
+++ b/tests/baselines/reference/useBeforeDeclaration_classDecorators.1.errors.txt
@@ -0,0 +1,147 @@
+useBeforeDeclaration_classDecorators.1.ts(7,6): error TS2449: Class 'C2' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(10,13): error TS2449: Class 'C3' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(29,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(30,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(31,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(32,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(33,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(35,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(36,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(37,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(38,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(39,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(44,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(45,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(46,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(47,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(48,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(50,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(51,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(52,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(53,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.1.ts(54,17): error TS2449: Class 'C6' used before its declaration.
+
+
+==== useBeforeDeclaration_classDecorators.1.ts (22 errors) ====
+    declare const dec: any;
+    
+    // ok
+    @dec(() => C1) class C1 { }
+    
+    // error
+    @dec(C2) class C2 { }
+         ~~
+!!! error TS2449: Class 'C2' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:7:16: 'C2' is declared here.
+    
+    // error
+    @dec((() => C3)()) class C3 { }
+                ~~
+!!! error TS2449: Class 'C3' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:10:26: 'C3' is declared here.
+    
+    // ok
+    class C4 {
+        @dec(() => C4) static method() {}
+        @dec(() => C4) static get x() { return this.y; }
+        @dec(() => C4) static set x(v) {}
+        @dec(() => C4) static y: any;
+        @dec(() => C4) static accessor z: any;
+    
+        @dec(() => C4) method() {}
+        @dec(() => C4) get x() { return this.y; }
+        @dec(() => C4) set x(v) {}
+        @dec(() => C4) y: any;
+        @dec(() => C4) accessor z: any;
+    }
+    
+    // error
+    class C5 {
+        @dec(C5) static method() {}
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:28:7: 'C5' is declared here.
+        @dec(C5) static get x() { return this.y; }
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:28:7: 'C5' is declared here.
+        @dec(C5) static set x(v) {}
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:28:7: 'C5' is declared here.
+        @dec(C5) static y: any;
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:28:7: 'C5' is declared here.
+        @dec(C5) static accessor z: any;
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:28:7: 'C5' is declared here.
+    
+        @dec(C5) method() {}
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:28:7: 'C5' is declared here.
+        @dec(C5) get x() { return this.y; }
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:28:7: 'C5' is declared here.
+        @dec(C5) set x(v) {}
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:28:7: 'C5' is declared here.
+        @dec(C5) y: any;
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:28:7: 'C5' is declared here.
+        @dec(C5) accessor z: any;
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:28:7: 'C5' is declared here.
+    }
+    
+    // error
+    class C6 {
+        @dec((() => C6)()) static method() {}
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:43:7: 'C6' is declared here.
+        @dec((() => C6)()) static get x() { return this.y; }
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:43:7: 'C6' is declared here.
+        @dec((() => C6)()) static set x(v) {}
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:43:7: 'C6' is declared here.
+        @dec((() => C6)()) static y: any;
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:43:7: 'C6' is declared here.
+        @dec((() => C6)()) static accessor z: any;
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:43:7: 'C6' is declared here.
+    
+        @dec((() => C6)()) method() {}
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:43:7: 'C6' is declared here.
+        @dec((() => C6)()) get x() { return this.y; }
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:43:7: 'C6' is declared here.
+        @dec((() => C6)()) set x(v) {}
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:43:7: 'C6' is declared here.
+        @dec((() => C6)()) y: any;
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:43:7: 'C6' is declared here.
+        @dec((() => C6)()) accessor z: any;
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.1.ts:43:7: 'C6' is declared here.
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/useBeforeDeclaration_classDecorators.2.errors.txt b/tests/baselines/reference/useBeforeDeclaration_classDecorators.2.errors.txt
new file mode 100644
index 0000000000000..567b26d168527
--- /dev/null
+++ b/tests/baselines/reference/useBeforeDeclaration_classDecorators.2.errors.txt
@@ -0,0 +1,203 @@
+useBeforeDeclaration_classDecorators.2.ts(7,6): error TS2449: Class 'C2' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(10,13): error TS2449: Class 'C3' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(16,5): error TS1207: Decorators cannot be applied to multiple get/set accessors of the same name.
+useBeforeDeclaration_classDecorators.2.ts(22,5): error TS1207: Decorators cannot be applied to multiple get/set accessors of the same name.
+useBeforeDeclaration_classDecorators.2.ts(33,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(34,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(35,5): error TS1207: Decorators cannot be applied to multiple get/set accessors of the same name.
+useBeforeDeclaration_classDecorators.2.ts(35,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(36,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(37,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(39,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(40,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(41,5): error TS1207: Decorators cannot be applied to multiple get/set accessors of the same name.
+useBeforeDeclaration_classDecorators.2.ts(41,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(42,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(43,10): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(46,22): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(47,25): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(48,18): error TS2449: Class 'C5' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(53,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(54,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(55,5): error TS1207: Decorators cannot be applied to multiple get/set accessors of the same name.
+useBeforeDeclaration_classDecorators.2.ts(55,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(56,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(57,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(59,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(60,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(61,5): error TS1207: Decorators cannot be applied to multiple get/set accessors of the same name.
+useBeforeDeclaration_classDecorators.2.ts(61,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(62,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(63,17): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(66,29): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(67,32): error TS2449: Class 'C6' used before its declaration.
+useBeforeDeclaration_classDecorators.2.ts(68,25): error TS2449: Class 'C6' used before its declaration.
+
+
+==== useBeforeDeclaration_classDecorators.2.ts (34 errors) ====
+    declare const dec: any;
+    
+    // ok
+    @dec(() => C1) class C1 { }
+    
+    // error
+    @dec(C2) class C2 { }
+         ~~
+!!! error TS2449: Class 'C2' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:7:16: 'C2' is declared here.
+    
+    // error
+    @dec((() => C3)()) class C3 { }
+                ~~
+!!! error TS2449: Class 'C3' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:10:26: 'C3' is declared here.
+    
+    // ok
+    class C4 {
+        @dec(() => C4) static method() {}
+        @dec(() => C4) static get x() { return this.y; }
+        @dec(() => C4) static set x(v) {}
+        ~
+!!! error TS1207: Decorators cannot be applied to multiple get/set accessors of the same name.
+        @dec(() => C4) static y: any;
+        @dec(() => C4) static accessor z: any;
+    
+        @dec(() => C4) method() {}
+        @dec(() => C4) get x() { return this.y; }
+        @dec(() => C4) set x(v) {}
+        ~
+!!! error TS1207: Decorators cannot be applied to multiple get/set accessors of the same name.
+        @dec(() => C4) y: any;
+        @dec(() => C4) accessor z: any;
+    
+        constructor(@dec(() => C4) a: any) {}
+        static method2(@dec(() => C4) a: any) {}
+        method2(@dec(() => C4) a: any) {}
+    }
+    
+    // error
+    class C5 {
+        @dec(C5) static method() {}
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+        @dec(C5) static get x() { return this.y; }
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+        @dec(C5) static set x(v) {}
+        ~
+!!! error TS1207: Decorators cannot be applied to multiple get/set accessors of the same name.
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+        @dec(C5) static y: any;
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+        @dec(C5) static accessor z: any;
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+    
+        @dec(C5) method() {}
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+        @dec(C5) get x() { return this.y; }
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+        @dec(C5) set x(v) {}
+        ~
+!!! error TS1207: Decorators cannot be applied to multiple get/set accessors of the same name.
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+        @dec(C5) y: any;
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+        @dec(C5) accessor z: any;
+             ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+    
+    
+        constructor(@dec(C5) a: any) {}
+                         ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+        static method2(@dec(C5) a: any) {}
+                            ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+        method2(@dec(C5) a: any) {}
+                     ~~
+!!! error TS2449: Class 'C5' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:32:7: 'C5' is declared here.
+    }
+    
+    // error
+    class C6 {
+        @dec((() => C6)()) static method() {}
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+        @dec((() => C6)()) static get x() { return this.y; }
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+        @dec((() => C6)()) static set x(v) {}
+        ~
+!!! error TS1207: Decorators cannot be applied to multiple get/set accessors of the same name.
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+        @dec((() => C6)()) static y: any;
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+        @dec((() => C6)()) static accessor z: any;
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+    
+        @dec((() => C6)()) method() {}
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+        @dec((() => C6)()) get x() { return this.y; }
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+        @dec((() => C6)()) set x(v) {}
+        ~
+!!! error TS1207: Decorators cannot be applied to multiple get/set accessors of the same name.
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+        @dec((() => C6)()) y: any;
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+        @dec((() => C6)()) accessor z: any;
+                    ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+    
+    
+        constructor(@dec((() => C6)()) a: any) {}
+                                ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+        static method2(@dec((() => C6)()) a: any) {}
+                                   ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+        method2(@dec((() => C6)()) a: any) {}
+                            ~~
+!!! error TS2449: Class 'C6' used before its declaration.
+!!! related TS2728 useBeforeDeclaration_classDecorators.2.ts:52:7: 'C6' is declared here.
+    }
+    
\ No newline at end of file
diff --git a/tests/cases/compiler/decoratorReferences.ts b/tests/cases/compiler/decoratorReferences.ts
index c6222e67fd929..faa257983d20f 100644
--- a/tests/cases/compiler/decoratorReferences.ts
+++ b/tests/cases/compiler/decoratorReferences.ts
@@ -2,7 +2,7 @@
 
 declare function y(...args: any[]): any;
 type T = number;
-@y(1 as T, C) // <-- T should be resolved to the type alias, not the type parameter of the class; C should resolve to the class
+@y(1 as T, () => C) // <-- T should be resolved to the type alias, not the type parameter of the class; C should resolve to the class
 class C<T> {
     @y(null as T) // <-- y should resolve to the function declaration, not the parameter; T should resolve to the type parameter of the class
     method(@y x, y) {} // <-- decorator y should be resolved at the class declaration, not the parameter.
diff --git a/tests/cases/compiler/useBeforeDeclaration_classDecorators.1.ts b/tests/cases/compiler/useBeforeDeclaration_classDecorators.1.ts
new file mode 100644
index 0000000000000..25c55dd0bcf51
--- /dev/null
+++ b/tests/cases/compiler/useBeforeDeclaration_classDecorators.1.ts
@@ -0,0 +1,59 @@
+// @target: esnext
+// @noEmit: true
+// @noTypesAndSymbols: true
+
+declare const dec: any;
+
+// ok
+@dec(() => C1) class C1 { }
+
+// error
+@dec(C2) class C2 { }
+
+// error
+@dec((() => C3)()) class C3 { }
+
+// ok
+class C4 {
+    @dec(() => C4) static method() {}
+    @dec(() => C4) static get x() { return this.y; }
+    @dec(() => C4) static set x(v) {}
+    @dec(() => C4) static y: any;
+    @dec(() => C4) static accessor z: any;
+
+    @dec(() => C4) method() {}
+    @dec(() => C4) get x() { return this.y; }
+    @dec(() => C4) set x(v) {}
+    @dec(() => C4) y: any;
+    @dec(() => C4) accessor z: any;
+}
+
+// error
+class C5 {
+    @dec(C5) static method() {}
+    @dec(C5) static get x() { return this.y; }
+    @dec(C5) static set x(v) {}
+    @dec(C5) static y: any;
+    @dec(C5) static accessor z: any;
+
+    @dec(C5) method() {}
+    @dec(C5) get x() { return this.y; }
+    @dec(C5) set x(v) {}
+    @dec(C5) y: any;
+    @dec(C5) accessor z: any;
+}
+
+// error
+class C6 {
+    @dec((() => C6)()) static method() {}
+    @dec((() => C6)()) static get x() { return this.y; }
+    @dec((() => C6)()) static set x(v) {}
+    @dec((() => C6)()) static y: any;
+    @dec((() => C6)()) static accessor z: any;
+
+    @dec((() => C6)()) method() {}
+    @dec((() => C6)()) get x() { return this.y; }
+    @dec((() => C6)()) set x(v) {}
+    @dec((() => C6)()) y: any;
+    @dec((() => C6)()) accessor z: any;
+}
diff --git a/tests/cases/compiler/useBeforeDeclaration_classDecorators.2.ts b/tests/cases/compiler/useBeforeDeclaration_classDecorators.2.ts
new file mode 100644
index 0000000000000..e3968e99b2d50
--- /dev/null
+++ b/tests/cases/compiler/useBeforeDeclaration_classDecorators.2.ts
@@ -0,0 +1,74 @@
+// @target: esnext
+// @noEmit: true
+// @noTypesAndSymbols: true
+// @experimentalDecorators: true
+
+declare const dec: any;
+
+// ok
+@dec(() => C1) class C1 { }
+
+// error
+@dec(C2) class C2 { }
+
+// error
+@dec((() => C3)()) class C3 { }
+
+// ok
+class C4 {
+    @dec(() => C4) static method() {}
+    @dec(() => C4) static get x() { return this.y; }
+    @dec(() => C4) static set x(v) {}
+    @dec(() => C4) static y: any;
+    @dec(() => C4) static accessor z: any;
+
+    @dec(() => C4) method() {}
+    @dec(() => C4) get x() { return this.y; }
+    @dec(() => C4) set x(v) {}
+    @dec(() => C4) y: any;
+    @dec(() => C4) accessor z: any;
+
+    constructor(@dec(() => C4) a: any) {}
+    static method2(@dec(() => C4) a: any) {}
+    method2(@dec(() => C4) a: any) {}
+}
+
+// error
+class C5 {
+    @dec(C5) static method() {}
+    @dec(C5) static get x() { return this.y; }
+    @dec(C5) static set x(v) {}
+    @dec(C5) static y: any;
+    @dec(C5) static accessor z: any;
+
+    @dec(C5) method() {}
+    @dec(C5) get x() { return this.y; }
+    @dec(C5) set x(v) {}
+    @dec(C5) y: any;
+    @dec(C5) accessor z: any;
+
+
+    constructor(@dec(C5) a: any) {}
+    static method2(@dec(C5) a: any) {}
+    method2(@dec(C5) a: any) {}
+}
+
+// error
+class C6 {
+    @dec((() => C6)()) static method() {}
+    @dec((() => C6)()) static get x() { return this.y; }
+    @dec((() => C6)()) static set x(v) {}
+    @dec((() => C6)()) static y: any;
+    @dec((() => C6)()) static accessor z: any;
+
+    @dec((() => C6)()) method() {}
+    @dec((() => C6)()) get x() { return this.y; }
+    @dec((() => C6)()) set x(v) {}
+    @dec((() => C6)()) y: any;
+    @dec((() => C6)()) accessor z: any;
+
+
+    constructor(@dec((() => C6)()) a: any) {}
+    static method2(@dec((() => C6)()) a: any) {}
+    method2(@dec((() => C6)()) a: any) {}
+}