diff --git a/src/compiler/transformers/ts.ts b/src/compiler/transformers/ts.ts
index d413a835d0d86..cc8481538da93 100644
--- a/src/compiler/transformers/ts.ts
+++ b/src/compiler/transformers/ts.ts
@@ -1873,6 +1873,9 @@ namespace ts {
         }
 
         function visitPropertyDeclaration(node: PropertyDeclaration) {
+            if (node.flags & NodeFlags.Ambient) {
+                return undefined;
+            }
             const updated = updateProperty(
                 node,
                 /*decorators*/ undefined,
diff --git a/tests/baselines/reference/definePropertyES5.js b/tests/baselines/reference/definePropertyES5.js
index a0bc4a64db48a..b61e8c11465ad 100644
--- a/tests/baselines/reference/definePropertyES5.js
+++ b/tests/baselines/reference/definePropertyES5.js
@@ -6,6 +6,7 @@ class A {
     ["computed"] = 13
     ;[x] = 14
     m() { }
+    declare notEmitted: boolean;
 }
 
 
diff --git a/tests/baselines/reference/definePropertyES5.symbols b/tests/baselines/reference/definePropertyES5.symbols
index f9afa02868793..48ec310926f36 100644
--- a/tests/baselines/reference/definePropertyES5.symbols
+++ b/tests/baselines/reference/definePropertyES5.symbols
@@ -21,5 +21,8 @@ class A {
 
     m() { }
 >m : Symbol(A.m, Decl(definePropertyES5.ts, 5, 13))
+
+    declare notEmitted: boolean;
+>notEmitted : Symbol(A.notEmitted, Decl(definePropertyES5.ts, 6, 11))
 }
 
diff --git a/tests/baselines/reference/definePropertyES5.types b/tests/baselines/reference/definePropertyES5.types
index 3f82787c13a34..7fffb77b74c45 100644
--- a/tests/baselines/reference/definePropertyES5.types
+++ b/tests/baselines/reference/definePropertyES5.types
@@ -25,5 +25,8 @@ class A {
 
     m() { }
 >m : () => void
+
+    declare notEmitted: boolean;
+>notEmitted : boolean
 }
 
diff --git a/tests/baselines/reference/definePropertyESNext.js b/tests/baselines/reference/definePropertyESNext.js
new file mode 100644
index 0000000000000..5fbd2fad7a93f
--- /dev/null
+++ b/tests/baselines/reference/definePropertyESNext.js
@@ -0,0 +1,46 @@
+//// [definePropertyESNext.ts]
+var x: "p" = "p"
+class A {
+    a = 12
+    b
+    ["computed"] = 13
+    ;[x] = 14
+    m() { }
+    constructor(public readonly y: number) { }
+    declare notEmitted;
+}
+class B {
+}
+class C extends B {
+    z = this.ka
+    constructor(public ka: number) {
+        super()
+    }
+    ki = this.ka
+}
+
+
+//// [definePropertyESNext.js]
+var x = "p";
+class A {
+    y;
+    a = 12;
+    b;
+    ["computed"] = 13;
+    [x] = 14;
+    m() { }
+    constructor(y) {
+        this.y = y;
+    }
+}
+class B {
+}
+class C extends B {
+    ka;
+    z = this.ka;
+    constructor(ka) {
+        super();
+        this.ka = ka;
+    }
+    ki = this.ka;
+}
diff --git a/tests/baselines/reference/definePropertyESNext.symbols b/tests/baselines/reference/definePropertyESNext.symbols
new file mode 100644
index 0000000000000..56463362d4ed3
--- /dev/null
+++ b/tests/baselines/reference/definePropertyESNext.symbols
@@ -0,0 +1,56 @@
+=== tests/cases/conformance/classes/propertyMemberDeclarations/definePropertyESNext.ts ===
+var x: "p" = "p"
+>x : Symbol(x, Decl(definePropertyESNext.ts, 0, 3))
+
+class A {
+>A : Symbol(A, Decl(definePropertyESNext.ts, 0, 16))
+
+    a = 12
+>a : Symbol(A.a, Decl(definePropertyESNext.ts, 1, 9))
+
+    b
+>b : Symbol(A.b, Decl(definePropertyESNext.ts, 2, 10))
+
+    ["computed"] = 13
+>["computed"] : Symbol(A["computed"], Decl(definePropertyESNext.ts, 3, 5))
+>"computed" : Symbol(A["computed"], Decl(definePropertyESNext.ts, 3, 5))
+
+    ;[x] = 14
+>[x] : Symbol(A[x], Decl(definePropertyESNext.ts, 5, 5))
+>x : Symbol(x, Decl(definePropertyESNext.ts, 0, 3))
+
+    m() { }
+>m : Symbol(A.m, Decl(definePropertyESNext.ts, 5, 13))
+
+    constructor(public readonly y: number) { }
+>y : Symbol(A.y, Decl(definePropertyESNext.ts, 7, 16))
+
+    declare notEmitted;
+>notEmitted : Symbol(A.notEmitted, Decl(definePropertyESNext.ts, 7, 46))
+}
+class B {
+>B : Symbol(B, Decl(definePropertyESNext.ts, 9, 1))
+}
+class C extends B {
+>C : Symbol(C, Decl(definePropertyESNext.ts, 11, 1))
+>B : Symbol(B, Decl(definePropertyESNext.ts, 9, 1))
+
+    z = this.ka
+>z : Symbol(C.z, Decl(definePropertyESNext.ts, 12, 19))
+>this.ka : Symbol(C.ka, Decl(definePropertyESNext.ts, 14, 16))
+>this : Symbol(C, Decl(definePropertyESNext.ts, 11, 1))
+>ka : Symbol(C.ka, Decl(definePropertyESNext.ts, 14, 16))
+
+    constructor(public ka: number) {
+>ka : Symbol(C.ka, Decl(definePropertyESNext.ts, 14, 16))
+
+        super()
+>super : Symbol(B, Decl(definePropertyESNext.ts, 9, 1))
+    }
+    ki = this.ka
+>ki : Symbol(C.ki, Decl(definePropertyESNext.ts, 16, 5))
+>this.ka : Symbol(C.ka, Decl(definePropertyESNext.ts, 14, 16))
+>this : Symbol(C, Decl(definePropertyESNext.ts, 11, 1))
+>ka : Symbol(C.ka, Decl(definePropertyESNext.ts, 14, 16))
+}
+
diff --git a/tests/baselines/reference/definePropertyESNext.types b/tests/baselines/reference/definePropertyESNext.types
new file mode 100644
index 0000000000000..303387461a5af
--- /dev/null
+++ b/tests/baselines/reference/definePropertyESNext.types
@@ -0,0 +1,61 @@
+=== tests/cases/conformance/classes/propertyMemberDeclarations/definePropertyESNext.ts ===
+var x: "p" = "p"
+>x : "p"
+>"p" : "p"
+
+class A {
+>A : A
+
+    a = 12
+>a : number
+>12 : 12
+
+    b
+>b : any
+
+    ["computed"] = 13
+>["computed"] : number
+>"computed" : "computed"
+>13 : 13
+
+    ;[x] = 14
+>[x] : number
+>x : "p"
+>14 : 14
+
+    m() { }
+>m : () => void
+
+    constructor(public readonly y: number) { }
+>y : number
+
+    declare notEmitted;
+>notEmitted : any
+}
+class B {
+>B : B
+}
+class C extends B {
+>C : C
+>B : B
+
+    z = this.ka
+>z : number
+>this.ka : number
+>this : this
+>ka : number
+
+    constructor(public ka: number) {
+>ka : number
+
+        super()
+>super() : void
+>super : typeof B
+    }
+    ki = this.ka
+>ki : number
+>this.ka : number
+>this : this
+>ka : number
+}
+
diff --git a/tests/baselines/reference/derivedUninitializedPropertyDeclaration.js b/tests/baselines/reference/derivedUninitializedPropertyDeclaration.js
index 471cd5bbf1d18..48715eefe0c4b 100644
--- a/tests/baselines/reference/derivedUninitializedPropertyDeclaration.js
+++ b/tests/baselines/reference/derivedUninitializedPropertyDeclaration.js
@@ -113,9 +113,7 @@ var BDBang = /** @class */ (function (_super) {
 var BOther = /** @class */ (function (_super) {
     __extends(BOther, _super);
     function BOther() {
-        var _this = _super !== null && _super.apply(this, arguments) || this;
-        _this.property = 'y'; // initialiser not allowed with declare
-        return _this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     BOther.prototype.m = function () { return 2; }; // not allowed on methods
     return BOther;
diff --git a/tests/baselines/reference/illegalModifiersOnClassElements.js b/tests/baselines/reference/illegalModifiersOnClassElements.js
index b87c822738b88..1650d65aa7080 100644
--- a/tests/baselines/reference/illegalModifiersOnClassElements.js
+++ b/tests/baselines/reference/illegalModifiersOnClassElements.js
@@ -7,7 +7,6 @@ class C {
 //// [illegalModifiersOnClassElements.js]
 var C = /** @class */ (function () {
     function C() {
-        this.foo = 1;
         this.bar = 1;
     }
     return C;
diff --git a/tests/cases/conformance/classes/propertyMemberDeclarations/definePropertyES5.ts b/tests/cases/conformance/classes/propertyMemberDeclarations/definePropertyES5.ts
index 73e1ee515d1d8..a2338889134ca 100644
--- a/tests/cases/conformance/classes/propertyMemberDeclarations/definePropertyES5.ts
+++ b/tests/cases/conformance/classes/propertyMemberDeclarations/definePropertyES5.ts
@@ -7,4 +7,5 @@ class A {
     ["computed"] = 13
     ;[x] = 14
     m() { }
+    declare notEmitted: boolean;
 }
diff --git a/tests/cases/conformance/classes/propertyMemberDeclarations/definePropertyESNext.ts b/tests/cases/conformance/classes/propertyMemberDeclarations/definePropertyESNext.ts
new file mode 100644
index 0000000000000..4bfd516229f05
--- /dev/null
+++ b/tests/cases/conformance/classes/propertyMemberDeclarations/definePropertyESNext.ts
@@ -0,0 +1,21 @@
+// @target: esnext
+// @useDefineForClassFields: true
+var x: "p" = "p"
+class A {
+    a = 12
+    b
+    ["computed"] = 13
+    ;[x] = 14
+    m() { }
+    constructor(public readonly y: number) { }
+    declare notEmitted;
+}
+class B {
+}
+class C extends B {
+    z = this.ka
+    constructor(public ka: number) {
+        super()
+    }
+    ki = this.ka
+}