diff --git a/benchmarks/bm.debounce.ts b/benchmarks/bm.debounce.ts
index 4e00bca..611616d 100644
--- a/benchmarks/bm.debounce.ts
+++ b/benchmarks/bm.debounce.ts
@@ -11,6 +11,8 @@ export function bm_debounce(suite: Suite) {
   return suite.add(
     'file -> debounce',
     (d: IDeferred) => run(debounce(100, fromArray(a)), d),
-    {defer: true}
+    {
+      defer: true
+    }
   )
 }
diff --git a/src/operators/Combine.ts b/src/operators/Combine.ts
index cb7f31b..d798f07 100644
--- a/src/operators/Combine.ts
+++ b/src/operators/Combine.ts
@@ -81,6 +81,7 @@ class CombineObservable<T> implements IObservable<T> {
 export const combine = curry(
   <T>(selector: TSelector<T>, sources: IObservable<any>[]) =>
     new CombineObservable(selector, sources)
-) as {<T, R>(selector: TSelector<T>, sources: TSource): TResult<R>} & {
+) as {
+  <T, R>(selector: TSelector<T>, sources: TSource): TResult<R>
   <T, R>(selector: TSelector<T>): {(sources: TSource): TResult<R>}
 }
diff --git a/src/operators/Debounce.ts b/src/operators/Debounce.ts
index fc3efa3..5948656 100644
--- a/src/operators/Debounce.ts
+++ b/src/operators/Debounce.ts
@@ -58,6 +58,6 @@ export const debounce = curry(
   <T>(timeout: number, source: IObservable<T>) => new Debounce(timeout, source)
 ) as {
   <T>(timeout: number, source: IObservable<T>): IObservable<T>
-} & {
+
   <T>(timeout: number): {(source: IObservable<T>): IObservable<T>}
 }
diff --git a/src/operators/Delay.ts b/src/operators/Delay.ts
index e00fe85..d028c38 100644
--- a/src/operators/Delay.ts
+++ b/src/operators/Delay.ts
@@ -54,6 +54,7 @@ class DelayObservable<T> implements IObservable<T> {
 export const delay = curry(
   <T>(timeout: number, source: IObservable<T>): IObservable<T> =>
     new DelayObservable(timeout, source)
-) as {<T>(timeout: number, source: IObservable<T>): IObservable<T>} & {
+) as {
+  <T>(timeout: number, source: IObservable<T>): IObservable<T>
   <T>(timeout: number): {(source: IObservable<T>): IObservable<T>}
 }
diff --git a/src/operators/Filter.ts b/src/operators/Filter.ts
index c89ba53..2cefcba 100644
--- a/src/operators/Filter.ts
+++ b/src/operators/Filter.ts
@@ -43,6 +43,7 @@ export const filter = curry(function<T>(
   source: TSource<T>
 ) {
   return new FilterObservable(predicate, source)
-}) as {<T>(predicate: TPredicate<T>, source: TSource<T>): TResult<T>} & {
+}) as {
+  <T>(predicate: TPredicate<T>, source: TSource<T>): TResult<T>
   <T>(predicate: TPredicate<T>): {(source: TSource<T>): TResult<T>}
 }
diff --git a/src/operators/MergeMap.ts b/src/operators/MergeMap.ts
index 4e0de53..2f5ffef 100644
--- a/src/operators/MergeMap.ts
+++ b/src/operators/MergeMap.ts
@@ -13,21 +13,29 @@ import {just} from '../sources/Create'
 
 export type Project<T, S> = (t: T) => IObservable<S>
 
-// prettier-ignore
 export type mergeMapFunctionWithConcurrency = {
-  <T, S>(concurrency: IObservable<number>, project: Project<T, S>, source: IObservable<T>): IObservable<S>
-  <T, S>(concurrency: IObservable<number>): {(project: Project<T, S>, source: IObservable<T>): IObservable<S>}
-  <T, S>(concurrency: IObservable<number>): {(project: Project<T, S>): {(source: IObservable<T>): IObservable<S>}}
+  <T, S>(
+    concurrency: IObservable<number>,
+    project: Project<T, S>,
+    source: IObservable<T>
+  ): IObservable<S>
+  <T, S>(concurrency: IObservable<number>): {
+    (project: Project<T, S>, source: IObservable<T>): IObservable<S>
+  }
+  <T, S>(concurrency: IObservable<number>): {
+    (project: Project<T, S>): {(source: IObservable<T>): IObservable<S>}
+  }
 }
 
-// prettier-ignore
 export type mergeMapFunction = {
   <T, S>(project: Project<T, S>, source: IObservable<T>): IObservable<S>
   <T, S>(project: Project<T, S>, source: IObservable<T>): IObservable<S>
   <T, S>(project: Project<T, S>): {(source: IObservable<T>): IObservable<S>}
 }
-// prettier-ignore
-export type joinFunction = <T>(source: IObservable<IObservable<T>>) => IObservable<T>
+
+export type joinFunction = <T>(
+  source: IObservable<IObservable<T>>
+) => IObservable<T>
 
 class ConcurrencyObserver extends ErrorMixin(Virgin)
   implements IObserver<number> {
diff --git a/src/operators/Reduce.ts b/src/operators/Reduce.ts
index d2a5270..ffca51a 100644
--- a/src/operators/Reduce.ts
+++ b/src/operators/Reduce.ts
@@ -58,15 +58,15 @@ export const reduce = curry(function<T, R>(
   <T, R>(reducer: TReducer<T, R>, seed: TSeed<R>, source: TSource<T>): TResult<
     R
   >
-} & {
+
   <T, R>(reducer: TReducer<T, R>): {
     (seed: TSeed<R>, source: TSource<T>): TResult<R>
   }
-} & {
+
   <T, R>(reducer: TReducer<T, R>, seed: TSeed<R>): {
     (source: TSource<T>): TResult<R>
   }
-} & {
+
   <T, R>(reducer: TReducer<T, R>): {
     (seed: TSeed<R>): {(source: TSource<T>): TResult<R>}
   }
diff --git a/src/operators/Sample.ts b/src/operators/Sample.ts
index b816d52..9e3892e 100644
--- a/src/operators/Sample.ts
+++ b/src/operators/Sample.ts
@@ -101,15 +101,15 @@ export const sample = curry(function<T>(
   return new SampleObservable(f, sampler, sources)
 }) as {
   <T>(selector: TSelector<T>, sampler: TSampler, source: TSources): TResult<T>
-} & {
+
   <T>(selector: TSelector<T>): {
     (sampler: TSampler, source: TSources): TResult<T>
   }
-} & {
+
   <T>(selector: TSelector<T>, sampler: TSampler): {
     (source: TSources): TResult<T>
   }
-} & {
+
   <T>(selector: TSelector<T>): {
     (sampler: TSampler): {(source: TSources): TResult<T>}
   }
diff --git a/src/operators/Scan.ts b/src/operators/Scan.ts
index 4459627..2d0ccd0 100644
--- a/src/operators/Scan.ts
+++ b/src/operators/Scan.ts
@@ -54,15 +54,15 @@ export const scan = curry(function<T, V>(
   <T, R>(reducer: TReducer<T, R>, seed: TSeed<R>, source: TSource<T>): TResult<
     R
   >
-} & {
+
   <T, R>(reducer: TReducer<T, R>): {
     (seed: TSeed<R>, source: TSource<T>): TResult<R>
   }
-} & {
+
   <T, R>(reducer: TReducer<T, R>, seed: TSeed<R>): {
     (source: TSource<T>): TResult<R>
   }
-} & {
+
   <T, R>(reducer: TReducer<T, R>): {
     (seed: TSeed<R>): {(source: TSource<T>): TResult<R>}
   }
diff --git a/src/operators/SkipRepeats.ts b/src/operators/SkipRepeats.ts
index 81d6439..7fbbd46 100644
--- a/src/operators/SkipRepeats.ts
+++ b/src/operators/SkipRepeats.ts
@@ -49,6 +49,7 @@ export const skipRepeats = curry(function(
   source: IObservable<any>
 ) {
   return new SkipRepeatsObservable(hashFunction, source)
-}) as {<T>(cmp: TComparator<T>, source: TSource<T>): TResult<T>} & {
+}) as {
+  <T>(cmp: TComparator<T>, source: TSource<T>): TResult<T>
   <T>(cmp: TComparator<T>): {(source: TSource<T>): TResult<T>}
 }
diff --git a/src/operators/Slice.ts b/src/operators/Slice.ts
index a434932..6d14f9a 100644
--- a/src/operators/Slice.ts
+++ b/src/operators/Slice.ts
@@ -74,13 +74,13 @@ export const slice = curry(function(
   return new SliceObservable(start, count, source)
 }) as {
   <T>(start: number, count: number, source: IObservable<T>): IObservable<T>
-} & {
+
   <T>(start: number): {(count: number, source: IObservable<T>): IObservable<T>}
-} & {
+
   <T>(start: number, count: number): {
     (source: IObservable<T>): IObservable<T>
   }
-} & {
+
   <T>(start: number): {
     (count: number): {(source: IObservable<T>): IObservable<T>}
   }
diff --git a/src/operators/Switch.ts b/src/operators/Switch.ts
index ff40ee5..3c05a57 100644
--- a/src/operators/Switch.ts
+++ b/src/operators/Switch.ts
@@ -66,7 +66,7 @@ export const switchMap = curry(
   <T, K>(mapper: (t: K) => IObservable<T>, source: IObservable<K>): IObservable<
     T
   >
-} & {
+
   <T, K>(mapper: (t: K) => IObservable<T>): {
     (source: IObservable<K>): IObservable<T>
   }
diff --git a/src/sources/FromDOM.ts b/src/sources/FromDOM.ts
index a699089..5fa1637 100644
--- a/src/sources/FromDOM.ts
+++ b/src/sources/FromDOM.ts
@@ -37,6 +37,7 @@ class DOMObservable implements TResult {
 
 export const fromDOM = curry(function(element: EventTarget, name: string) {
   return new DOMObservable(name, element)
-}) as {(element: EventTarget, name: string): TResult} & {
+}) as {
+  (element: EventTarget, name: string): TResult
   (element: EventTarget): {(name: string): TResult}
 }