diff --git a/.changeset/gold-singers-hide.md b/.changeset/gold-singers-hide.md
new file mode 100644
index 00000000..63f9acb6
--- /dev/null
+++ b/.changeset/gold-singers-hide.md
@@ -0,0 +1,5 @@
+---
+"@millicast/sdk": patch
+---
+
+Aligning types for sourceId property within project method and global types .d.ts file
diff --git a/packages/millicast-sdk/src/View.js b/packages/millicast-sdk/src/View.js
index 6af6e3f7..c6f50bb7 100644
--- a/packages/millicast-sdk/src/View.js
+++ b/packages/millicast-sdk/src/View.js
@@ -158,7 +158,7 @@ export default class View extends BaseWebRTC {
 
   /**
    * Start projecting source in selected media ids.
-   * @param {String} sourceId                          - Selected source id.
+   * @param {String | null} sourceId                   - Selected source id.
    * @param {Array<Object>} mapping                    - Mapping of the source track ids to the receiver mids
    * @param {String} [mapping.trackId]                 - Track id from the source (received on the "active" event), if not set the media kind will be used instead.
    * @param {String} [mapping.media]                   - Track kind of the source ('audio' | 'video'), if not set the trackId will be used instead.
diff --git a/packages/millicast-sdk/src/types/index.d.ts b/packages/millicast-sdk/src/types/index.d.ts
index f5fe8cb7..826171a0 100644
--- a/packages/millicast-sdk/src/types/index.d.ts
+++ b/packages/millicast-sdk/src/types/index.d.ts
@@ -532,7 +532,7 @@ declare module '@millicast/sdk' {
     previousStats: ConnectionStats;
     /**
      * Initialize the statistics monitoring of the RTCPeerConnection.
-     * @param {statsIntervalMs} the interval, in ms, at which stats are returned to the user.  
+     * @param {statsIntervalMs} the interval, in ms, at which stats are returned to the user.
      */
     init(statsIntervalMs: number): void;
     /**
@@ -558,7 +558,7 @@ declare module '@millicast/sdk' {
 
   export type MediaStreamSource = {
     readonly streamId: string;
-    sourceId: string;
+    sourceId: string | null;
     readonly tracks: MediaTrackInfo[];
   }