diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index 370461abd8559..aa67a5973caeb 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -67,6 +67,7 @@ namespace ts {
         ["es2019.object", "lib.es2019.object.d.ts"],
         ["es2019.string", "lib.es2019.string.d.ts"],
         ["es2019.symbol", "lib.es2019.symbol.d.ts"],
+        ["es2019.intl", "lib.es2019.intl.d.ts"],
         ["es2020.bigint", "lib.es2020.bigint.d.ts"],
         ["es2020.date", "lib.es2020.date.d.ts"],
         ["es2020.promise", "lib.es2020.promise.d.ts"],
diff --git a/src/lib/es2017.intl.d.ts b/src/lib/es2017.intl.d.ts
index 8c0f3cbf7ceb4..2f9efc15fbbae 100644
--- a/src/lib/es2017.intl.d.ts
+++ b/src/lib/es2017.intl.d.ts
@@ -12,7 +12,6 @@ declare namespace Intl {
         timeZoneName: any
         weekday: any
         year: any
-        unknown: any
     }
 
     type DateTimeFormatPartTypes = keyof DateTimeFormatPartTypesRegistry;
diff --git a/src/lib/es2019.d.ts b/src/lib/es2019.d.ts
index 29212ecfe0f1b..e2c3925a3ec8d 100644
--- a/src/lib/es2019.d.ts
+++ b/src/lib/es2019.d.ts
@@ -3,3 +3,4 @@
 /// <reference lib="es2019.object" />
 /// <reference lib="es2019.string" />
 /// <reference lib="es2019.symbol" />
+/// <reference lib="es2019.intl" />
diff --git a/src/lib/es2019.intl.d.ts b/src/lib/es2019.intl.d.ts
new file mode 100644
index 0000000000000..32993edc4d8cd
--- /dev/null
+++ b/src/lib/es2019.intl.d.ts
@@ -0,0 +1,5 @@
+declare namespace Intl {
+    interface DateTimeFormatPartTypesRegistry {
+        unknown: any
+    }
+}
diff --git a/src/lib/libs.json b/src/lib/libs.json
index 305c6e3030a90..a14e435290012 100644
--- a/src/lib/libs.json
+++ b/src/lib/libs.json
@@ -43,6 +43,7 @@
         "es2019.object",
         "es2019.string",
         "es2019.symbol",
+        "es2019.intl",
         "es2020.bigint",
         "es2020.date",
         "es2020.promise",