diff --git a/compat/operators/concat.ts b/compat/operators/concat.ts
new file mode 100644
index 0000000000..2fb1fd3e2e
--- /dev/null
+++ b/compat/operators/concat.ts
@@ -0,0 +1,16 @@
+import {  concat as concatStatic, Observable, ObservableInput, OperatorFunction, MonoTypeOperatorFunction, SchedulerLike } from 'rxjs';
+
+/* tslint:disable:max-line-length */
+export function concat<T>(scheduler?: SchedulerLike): MonoTypeOperatorFunction<T>;
+export function concat<T, T2>(v2: ObservableInput<T2>, scheduler?: SchedulerLike): OperatorFunction<T, T | T2>;
+export function concat<T, T2, T3>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, scheduler?: SchedulerLike): OperatorFunction<T, T | T2 | T3>;
+export function concat<T, T2, T3, T4>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, scheduler?: SchedulerLike): OperatorFunction<T, T | T2 | T3 | T4>;
+export function concat<T, T2, T3, T4, T5>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>, scheduler?: SchedulerLike): OperatorFunction<T, T | T2 | T3 | T4 | T5>;
+export function concat<T, T2, T3, T4, T5, T6>(v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>, v6: ObservableInput<T6>, scheduler?: SchedulerLike): OperatorFunction<T, T | T2 | T3 | T4 | T5 | T6>;
+export function concat<T>(...observables: Array<ObservableInput<T> | SchedulerLike>): MonoTypeOperatorFunction<T>;
+export function concat<T, R>(...observables: Array<ObservableInput<any> | SchedulerLike>): OperatorFunction<T, R>;
+/* tslint:enable:max-line-length */
+
+export function concat<T, R>(...observables: Array<ObservableInput<any> | SchedulerLike>): OperatorFunction<T, R> {
+  return (source: Observable<T>) => source.lift.call(concatStatic<T, R>(source, ...observables));
+}
diff --git a/legacy-reexport/operators/concat.ts b/legacy-reexport/operators/concat.ts
new file mode 100644
index 0000000000..d2b7050940
--- /dev/null
+++ b/legacy-reexport/operators/concat.ts
@@ -0,0 +1 @@
+export * from 'rxjs-compat/operators/concat';
\ No newline at end of file