diff --git a/src/parser/utilities.ts b/src/parser/utilities.ts
index 83e56d81631..f04f5f01bd7 100644
--- a/src/parser/utilities.ts
+++ b/src/parser/utilities.ts
@@ -4325,6 +4325,8 @@ namespace ts {
         switch (options.target) {
             case ScriptTarget.ESNext:
                 return "lib.esnext.full.d.ts";
+            case ScriptTarget.ES2018:
+                return "lib.es2018.full.d.ts";
             case ScriptTarget.ES2017:
                 return "lib.es2017.full.d.ts";
             case ScriptTarget.ES2016:
diff --git a/tests/baselines/reference/es2018ObjectAssign.js b/tests/baselines/reference/es2018ObjectAssign.js
new file mode 100644
index 00000000000..4ad3dc3c8e7
--- /dev/null
+++ b/tests/baselines/reference/es2018ObjectAssign.js
@@ -0,0 +1,9 @@
+//// [es2018ObjectAssign.ts]
+const test = Object.assign({}, { test: true });
+
+declare const p: Promise<number>;
+p.finally();
+
+//// [es2018ObjectAssign.js]
+const test = Object.assign({}, { test: true });
+p.finally();
diff --git a/tests/baselines/reference/es2018ObjectAssign.symbols b/tests/baselines/reference/es2018ObjectAssign.symbols
new file mode 100644
index 00000000000..3ed140cb570
--- /dev/null
+++ b/tests/baselines/reference/es2018ObjectAssign.symbols
@@ -0,0 +1,17 @@
+=== tests/cases/compiler/es2018ObjectAssign.ts ===
+const test = Object.assign({}, { test: true });
+>test : Symbol(test, Decl(es2018ObjectAssign.ts, 0, 5))
+>Object.assign : Symbol(ObjectConstructor.assign, Decl(lib.es2015.core.d.ts, --, --), Decl(lib.es2015.core.d.ts, --, --), Decl(lib.es2015.core.d.ts, --, --), Decl(lib.es2015.core.d.ts, --, --))
+>Object : Symbol(Object, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>assign : Symbol(ObjectConstructor.assign, Decl(lib.es2015.core.d.ts, --, --), Decl(lib.es2015.core.d.ts, --, --), Decl(lib.es2015.core.d.ts, --, --), Decl(lib.es2015.core.d.ts, --, --))
+>test : Symbol(test, Decl(es2018ObjectAssign.ts, 0, 32))
+
+declare const p: Promise<number>;
+>p : Symbol(p, Decl(es2018ObjectAssign.ts, 2, 13))
+>Promise : Symbol(Promise, Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2018.promise.d.ts, --, --))
+
+p.finally();
+>p.finally : Symbol(Promise.finally, Decl(lib.es2018.promise.d.ts, --, --))
+>p : Symbol(p, Decl(es2018ObjectAssign.ts, 2, 13))
+>finally : Symbol(Promise.finally, Decl(lib.es2018.promise.d.ts, --, --))
+
diff --git a/tests/baselines/reference/es2018ObjectAssign.types b/tests/baselines/reference/es2018ObjectAssign.types
new file mode 100644
index 00000000000..92ac3d760a3
--- /dev/null
+++ b/tests/baselines/reference/es2018ObjectAssign.types
@@ -0,0 +1,22 @@
+=== tests/cases/compiler/es2018ObjectAssign.ts ===
+const test = Object.assign({}, { test: true });
+>test : { test: boolean; }
+>Object.assign({}, { test: true }) : { test: boolean; }
+>Object.assign : { <T, U>(target: T, source: U): T & U; <T, U, V>(target: T, source1: U, source2: V): T & U & V; <T, U, V, W>(target: T, source1: U, source2: V, source3: W): T & U & V & W; (target: object, ...sources: any[]): any; }
+>Object : ObjectConstructor
+>assign : { <T, U>(target: T, source: U): T & U; <T, U, V>(target: T, source1: U, source2: V): T & U & V; <T, U, V, W>(target: T, source1: U, source2: V, source3: W): T & U & V & W; (target: object, ...sources: any[]): any; }
+>{} : {}
+>{ test: true } : { test: true; }
+>test : true
+>true : true
+
+declare const p: Promise<number>;
+>p : Promise<number>
+>Promise : Promise<T>
+
+p.finally();
+>p.finally() : Promise<number>
+>p.finally : (onfinally?: () => void) => Promise<number>
+>p : Promise<number>
+>finally : (onfinally?: () => void) => Promise<number>
+
diff --git a/tests/cases/compiler/es2018ObjectAssign.ts b/tests/cases/compiler/es2018ObjectAssign.ts
new file mode 100644
index 00000000000..314315b42b4
--- /dev/null
+++ b/tests/cases/compiler/es2018ObjectAssign.ts
@@ -0,0 +1,6 @@
+// @target: es2018
+
+const test = Object.assign({}, { test: true });
+
+declare const p: Promise<number>;
+p.finally();
\ No newline at end of file