diff --git a/bin/tsc.js b/bin/tsc.js
index 8a47fd26443..2bde9314b4d 100644
--- a/bin/tsc.js
+++ b/bin/tsc.js
@@ -13005,15 +13005,30 @@ var ts;
                     return type;
                 }
                 var prototypeProperty = getPropertyOfType(rightType, "prototype");
-                if (!prototypeProperty) {
-                    return type;
+                if (prototypeProperty) {
+                    var targetType = getTypeOfSymbol(prototypeProperty);
+                    if (targetType !== anyType) {
+                        if (isTypeSubtypeOf(targetType, type)) {
+                            return targetType;
+                        }
+                        if (type.flags & 16384) {
+                            return getUnionType(ts.filter(type.types, function (t) { return isTypeSubtypeOf(t, targetType); }));
+                        }
+                    }
                 }
-                var targetType = getTypeOfSymbol(prototypeProperty);
-                if (isTypeSubtypeOf(targetType, type)) {
-                    return targetType;
+                var constructSignatures;
+                if (rightType.flags & 2048) {
+                    constructSignatures = resolveDeclaredMembers(rightType).declaredConstructSignatures;
                 }
-                if (type.flags & 16384) {
-                    return getUnionType(ts.filter(type.types, function (t) { return isTypeSubtypeOf(t, targetType); }));
+                else if (rightType.flags & 32768) {
+                    constructSignatures = getSignaturesOfType(rightType, 1);
+                }
+                if (constructSignatures && constructSignatures.length !== 0) {
+                    var instanceType = getUnionType(ts.map(constructSignatures, function (signature) { return getReturnTypeOfSignature(getErasedSignature(signature)); }));
+                    if (type.flags & 16384) {
+                        return getUnionType(ts.filter(type.types, function (t) { return isTypeSubtypeOf(t, instanceType); }));
+                    }
+                    return instanceType;
                 }
                 return type;
             }
@@ -23260,15 +23275,6 @@ var ts;
                 scopeEmitEnd();
                 if (thisNodeIsDecorated) {
                     write(";");
-                    if (node.name) {
-                        writeLine();
-                        write("Object.defineProperty(");
-                        emitDeclarationName(node);
-                        write(", \"name\", { value: \"");
-                        emitDeclarationName(node);
-                        write("\", configurable: true });");
-                        writeLine();
-                    }
                 }
                 if (isClassExpressionWithStaticProperties) {
                     for (var _a = 0; _a < staticProperties.length; _a++) {
diff --git a/bin/tsserver.js b/bin/tsserver.js
index 7538e43029a..1707ef70411 100644
--- a/bin/tsserver.js
+++ b/bin/tsserver.js
@@ -13389,15 +13389,30 @@ var ts;
                     return type;
                 }
                 var prototypeProperty = getPropertyOfType(rightType, "prototype");
-                if (!prototypeProperty) {
-                    return type;
+                if (prototypeProperty) {
+                    var targetType = getTypeOfSymbol(prototypeProperty);
+                    if (targetType !== anyType) {
+                        if (isTypeSubtypeOf(targetType, type)) {
+                            return targetType;
+                        }
+                        if (type.flags & 16384) {
+                            return getUnionType(ts.filter(type.types, function (t) { return isTypeSubtypeOf(t, targetType); }));
+                        }
+                    }
                 }
-                var targetType = getTypeOfSymbol(prototypeProperty);
-                if (isTypeSubtypeOf(targetType, type)) {
-                    return targetType;
+                var constructSignatures;
+                if (rightType.flags & 2048) {
+                    constructSignatures = resolveDeclaredMembers(rightType).declaredConstructSignatures;
                 }
-                if (type.flags & 16384) {
-                    return getUnionType(ts.filter(type.types, function (t) { return isTypeSubtypeOf(t, targetType); }));
+                else if (rightType.flags & 32768) {
+                    constructSignatures = getSignaturesOfType(rightType, 1);
+                }
+                if (constructSignatures && constructSignatures.length !== 0) {
+                    var instanceType = getUnionType(ts.map(constructSignatures, function (signature) { return getReturnTypeOfSignature(getErasedSignature(signature)); }));
+                    if (type.flags & 16384) {
+                        return getUnionType(ts.filter(type.types, function (t) { return isTypeSubtypeOf(t, instanceType); }));
+                    }
+                    return instanceType;
                 }
                 return type;
             }
@@ -23644,15 +23659,6 @@ var ts;
                 scopeEmitEnd();
                 if (thisNodeIsDecorated) {
                     write(";");
-                    if (node.name) {
-                        writeLine();
-                        write("Object.defineProperty(");
-                        emitDeclarationName(node);
-                        write(", \"name\", { value: \"");
-                        emitDeclarationName(node);
-                        write("\", configurable: true });");
-                        writeLine();
-                    }
                 }
                 if (isClassExpressionWithStaticProperties) {
                     for (var _a = 0; _a < staticProperties.length; _a++) {
diff --git a/bin/typescript.js b/bin/typescript.js
index 9cee921f435..ba375bc4096 100644
--- a/bin/typescript.js
+++ b/bin/typescript.js
@@ -15732,17 +15732,34 @@ var ts;
                 }
                 // Target type is type of prototype property
                 var prototypeProperty = getPropertyOfType(rightType, "prototype");
-                if (!prototypeProperty) {
-                    return type;
+                if (prototypeProperty) {
+                    var targetType = getTypeOfSymbol(prototypeProperty);
+                    if (targetType !== anyType) {
+                        // Narrow to the target type if it's a subtype of the current type
+                        if (isTypeSubtypeOf(targetType, type)) {
+                            return targetType;
+                        }
+                        // If the current type is a union type, remove all constituents that aren't subtypes of the target.
+                        if (type.flags & 16384 /* Union */) {
+                            return getUnionType(ts.filter(type.types, function (t) { return isTypeSubtypeOf(t, targetType); }));
+                        }
+                    }
                 }
-                var targetType = getTypeOfSymbol(prototypeProperty);
-                // Narrow to target type if it is a subtype of current type
-                if (isTypeSubtypeOf(targetType, type)) {
-                    return targetType;
+                // Target type is type of construct signature
+                var constructSignatures;
+                if (rightType.flags & 2048 /* Interface */) {
+                    constructSignatures = resolveDeclaredMembers(rightType).declaredConstructSignatures;
                 }
-                // If current type is a union type, remove all constituents that aren't subtypes of target type
-                if (type.flags & 16384 /* Union */) {
-                    return getUnionType(ts.filter(type.types, function (t) { return isTypeSubtypeOf(t, targetType); }));
+                else if (rightType.flags & 32768 /* Anonymous */) {
+                    constructSignatures = getSignaturesOfType(rightType, 1 /* Construct */);
+                }
+                if (constructSignatures && constructSignatures.length !== 0) {
+                    var instanceType = getUnionType(ts.map(constructSignatures, function (signature) { return getReturnTypeOfSignature(getErasedSignature(signature)); }));
+                    // Pickup type from union types
+                    if (type.flags & 16384 /* Union */) {
+                        return getUnionType(ts.filter(type.types, function (t) { return isTypeSubtypeOf(t, instanceType); }));
+                    }
+                    return instanceType;
                 }
                 return type;
             }
@@ -27577,6 +27594,7 @@ var ts;
                 writeLine();
                 emitToken(15 /* CloseBraceToken */, node.members.end);
                 scopeEmitEnd();
+                // TODO(rbuckton): Need to go back to `let _a = class C {}` approach, removing the defineProperty call for now.
                 // For a decorated class, we need to assign its name (if it has one). This is because we emit
                 // the class as a class expression to avoid the double-binding of the identifier:
                 //
@@ -27586,15 +27604,6 @@ var ts;
                 //
                 if (thisNodeIsDecorated) {
                     write(";");
-                    if (node.name) {
-                        writeLine();
-                        write("Object.defineProperty(");
-                        emitDeclarationName(node);
-                        write(", \"name\", { value: \"");
-                        emitDeclarationName(node);
-                        write("\", configurable: true });");
-                        writeLine();
-                    }
                 }
                 // Emit static property assignment. Because classDeclaration is lexically evaluated,
                 // it is safe to emit static property assignment after classDeclaration
diff --git a/bin/typescriptServices.js b/bin/typescriptServices.js
index 9cee921f435..ba375bc4096 100644
--- a/bin/typescriptServices.js
+++ b/bin/typescriptServices.js
@@ -15732,17 +15732,34 @@ var ts;
                 }
                 // Target type is type of prototype property
                 var prototypeProperty = getPropertyOfType(rightType, "prototype");
-                if (!prototypeProperty) {
-                    return type;
+                if (prototypeProperty) {
+                    var targetType = getTypeOfSymbol(prototypeProperty);
+                    if (targetType !== anyType) {
+                        // Narrow to the target type if it's a subtype of the current type
+                        if (isTypeSubtypeOf(targetType, type)) {
+                            return targetType;
+                        }
+                        // If the current type is a union type, remove all constituents that aren't subtypes of the target.
+                        if (type.flags & 16384 /* Union */) {
+                            return getUnionType(ts.filter(type.types, function (t) { return isTypeSubtypeOf(t, targetType); }));
+                        }
+                    }
                 }
-                var targetType = getTypeOfSymbol(prototypeProperty);
-                // Narrow to target type if it is a subtype of current type
-                if (isTypeSubtypeOf(targetType, type)) {
-                    return targetType;
+                // Target type is type of construct signature
+                var constructSignatures;
+                if (rightType.flags & 2048 /* Interface */) {
+                    constructSignatures = resolveDeclaredMembers(rightType).declaredConstructSignatures;
                 }
-                // If current type is a union type, remove all constituents that aren't subtypes of target type
-                if (type.flags & 16384 /* Union */) {
-                    return getUnionType(ts.filter(type.types, function (t) { return isTypeSubtypeOf(t, targetType); }));
+                else if (rightType.flags & 32768 /* Anonymous */) {
+                    constructSignatures = getSignaturesOfType(rightType, 1 /* Construct */);
+                }
+                if (constructSignatures && constructSignatures.length !== 0) {
+                    var instanceType = getUnionType(ts.map(constructSignatures, function (signature) { return getReturnTypeOfSignature(getErasedSignature(signature)); }));
+                    // Pickup type from union types
+                    if (type.flags & 16384 /* Union */) {
+                        return getUnionType(ts.filter(type.types, function (t) { return isTypeSubtypeOf(t, instanceType); }));
+                    }
+                    return instanceType;
                 }
                 return type;
             }
@@ -27577,6 +27594,7 @@ var ts;
                 writeLine();
                 emitToken(15 /* CloseBraceToken */, node.members.end);
                 scopeEmitEnd();
+                // TODO(rbuckton): Need to go back to `let _a = class C {}` approach, removing the defineProperty call for now.
                 // For a decorated class, we need to assign its name (if it has one). This is because we emit
                 // the class as a class expression to avoid the double-binding of the identifier:
                 //
@@ -27586,15 +27604,6 @@ var ts;
                 //
                 if (thisNodeIsDecorated) {
                     write(";");
-                    if (node.name) {
-                        writeLine();
-                        write("Object.defineProperty(");
-                        emitDeclarationName(node);
-                        write(", \"name\", { value: \"");
-                        emitDeclarationName(node);
-                        write("\", configurable: true });");
-                        writeLine();
-                    }
                 }
                 // Emit static property assignment. Because classDeclaration is lexically evaluated,
                 // it is safe to emit static property assignment after classDeclaration