diff --git a/src/GSDPeak.ts b/src/GSDPeak.ts
index ffd0177..27e726b 100644
--- a/src/GSDPeak.ts
+++ b/src/GSDPeak.ts
@@ -1,5 +1,3 @@
-import { Shape1D } from 'ml-peak-shape-generator';
-
 export interface GSDPeak {
   id?: string;
   x: number;
@@ -18,8 +16,6 @@ export interface GSDPeak {
    */
   ddY: number;
 
-  shape: Shape1D;
-
   inflectionPoints: {
     from: { x: number; index: number };
     to: { x: number; index: number };
diff --git a/src/gsd.ts b/src/gsd.ts
index 5be2fa5..08c47c1 100644
--- a/src/gsd.ts
+++ b/src/gsd.ts
@@ -11,7 +11,6 @@ import {
 
 import { GSDPeak } from './GSDPeak';
 import { MakeMandatory } from './utils/MakeMandatory';
-import { MakeOptional } from './utils/MakeOptional';
 import { optimizeTop } from './utils/optimizeTop';
 
 export interface GSDOptions {
@@ -49,7 +48,7 @@ export interface GSDOptions {
   realTopDetection?: boolean;
 }
 export type GSDPeakID = MakeMandatory<GSDPeak, 'id'>;
-export type GSDPeakIDOptionalShape = MakeOptional<GSDPeak, 'shape'>;
+
 /**
  * Global spectra deconvolution
  * @param  data - Object data with x and y arrays. Values in x has to be growing
@@ -213,7 +212,7 @@ export function gsd(data: DataXY, options: GSDOptions = {}): GSDPeakID[] {
 
   let lastK = -1;
 
-  const peaks: GSDPeakIDOptionalShape[] = [];
+  const peaks: GSDPeakID[] = [];
   for (const minddYIndex of minddY) {
     let deltaX = x[minddYIndex];
     let possible = -1;
@@ -271,5 +270,5 @@ export function gsd(data: DataXY, options: GSDOptions = {}): GSDPeakID[] {
     return a.x - b.x;
   });
 
-  return peaks as GSDPeakID[];
+  return peaks;
 }
diff --git a/src/post/broadenPeaks.ts b/src/post/broadenPeaks.ts
index 7435981..0449f07 100644
--- a/src/post/broadenPeaks.ts
+++ b/src/post/broadenPeaks.ts
@@ -2,9 +2,8 @@ import { getShape1D, Shape1D } from 'ml-peak-shape-generator';
 
 import { GSDBroadenPeak } from '../GSDBroadenPeak';
 import { GSDPeak } from '../GSDPeak';
-import { MakeOptional } from '../utils/MakeOptional';
 
-type GSDPeakOptionalShape = MakeOptional<GSDPeak, 'shape'>;
+type GSDPeakOptionalShape = GSDPeak & { shape?: Shape1D };
 
 type GSDBroadenPeakWithID = GSDBroadenPeak & { id: string };
 type GSDBroadenPeakWithShape = GSDBroadenPeak & { shape: Shape1D };
diff --git a/src/post/joinBroadPeaks.ts b/src/post/joinBroadPeaks.ts
index fd8e257..714e97b 100644
--- a/src/post/joinBroadPeaks.ts
+++ b/src/post/joinBroadPeaks.ts
@@ -4,7 +4,6 @@ import { OptimizationOptions } from 'ml-spectra-fitting';
 
 import { GSDPeak } from '../GSDPeak';
 import { GSDPeakOptimized } from '../GSDPeakOptimized';
-import { MakeOptional } from '../utils/MakeOptional';
 import { addMissingIDs } from '../utils/addMissingIDs';
 import { addMissingShape } from '../utils/addMissingShape';
 
@@ -36,7 +35,7 @@ export interface JoinBroadPeaksOptions {
  * This function tries to join the peaks that seems to belong to a broad signal in a single broad peak.
  */
 
-export type GSDPeakOptionalShape = MakeOptional<GSDPeak, 'shape'>;
+export type GSDPeakOptionalShape = GSDPeak & { shape?: Shape1D };
 
 export function joinBroadPeaks<T extends GSDPeakOptionalShape>(
   peakList: T[],