diff --git a/README.md b/README.md
index 1e1c048..a12613a 100644
--- a/README.md
+++ b/README.md
@@ -44,8 +44,9 @@ console.log(result.tags)
 
 See [example](example) for more detailed usage.
 
-💡 Note: On IOS, writing exif into an Asset file will duplicate the image.
-Try to write to a local file first before saving!
+ℹ️ Note that on IOS, writing exif into an Asset file will duplicate the image. IOS does not allow writing exif into an Asset file directly.
+
+If you're getting the photo from a [camera](https://github.com/mrousavy/react-native-vision-camera/), write it into the output file first before saving to the Asset library!
 
 ## Contributing
 Contributions are welcome!
diff --git a/android/src/main/java/com/exify/ExifyModule.kt b/android/src/main/java/com/exify/ExifyModule.kt
index baae0bd..6d84a1a 100644
--- a/android/src/main/java/com/exify/ExifyModule.kt
+++ b/android/src/main/java/com/exify/ExifyModule.kt
@@ -80,7 +80,6 @@ class ExifyModule(reactContext: ReactApplicationContext) :
         }
 
         params.putString("uri", uri)
-        params.putString("assetId", null)
         params.putMap("tags", formatTags(exif))
 
         exif.saveAttributes()
diff --git a/ios/Exify.swift b/ios/Exify.swift
index 4c15b4d..a2a3b79 100644
--- a/ios/Exify.swift
+++ b/ios/Exify.swift
@@ -71,10 +71,10 @@ class Exify: NSObject {
             request.addResource(with: .photo, data: data, options: nil)
             request.creationDate = Date()
             
-            let assetId = request.placeholderForCreatedAsset!.localIdentifier
+            let newAssetId = request.placeholderForCreatedAsset!.localIdentifier
             resolve([
-              "uri": "ph://\(assetId)",
-              "assetId": assetId,
+              "uri": "ph://\(newAssetId)",
+              "assetId": newAssetId,
               "tags": getExifTags(from: metadata),
             ])
             
@@ -105,7 +105,6 @@ class Exify: NSObject {
 
         resolve([
           "uri": uri,
-          "assetId": nil,
           "tags": getExifTags(from: metadata),
         ])
         
diff --git a/ios/ExifyUtils.swift b/ios/ExifyUtils.swift
index 5ea1049..8721ab5 100644
--- a/ios/ExifyUtils.swift
+++ b/ios/ExifyUtils.swift
@@ -122,14 +122,14 @@ func updateMetadata(url: URL, with tags: [String: Any], completionHanlder: (NSDi
   
   let destinationData = NSMutableData()
 
-  guard let uiImage = UIImage(contentsOfFile: url.path),
-    let sourceType = CGImageSourceGetType(cgImageSource),
+  guard let sourceType = CGImageSourceGetType(cgImageSource),
     let destination = CGImageDestinationCreateWithData(destinationData, sourceType, 1, nil) else {
     return
   }
 
-  CGImageDestinationAddImage(destination, uiImage.cgImage!, metadata)
+  CGImageDestinationAddImageFromSource(destination, cgImageSource, 0, metadata)
   if CGImageDestinationFinalize(destination) {
     completionHanlder(metadata, destinationData as Data)
   }
 }
+
diff --git a/src/types.ts b/src/types.ts
index 26b78bb..c0175ae 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,5 +1,6 @@
 /**
  * From Android's ExifInterface Tags
+ * Normalized for both IOS and Android
  */
 export interface ExifTags {
   SensorLeftBorder?: number
@@ -147,15 +148,20 @@ export interface ExifTags {
 export interface ExifyWriteResult {
   /**
    * The URI of the image that was written.
-   * On IOS asset, this will be new URI created.
+   * On IOS: If input URI is an asset, this will be new URI created.
+   *
+   * This will return exactly the same as the input URI if the input URI is from a local file.
    */
-  uri?: string
+  uri: string
   /**
-   * Media Library Asset ID
+   * A newly created asset ID on IOS.
+   * Writing exif metadata into an asset file will create a new asset file.
+   *
+   * @platform ios
    */
-  assetId?: string | null
+  assetId?: string
   /**
-   * Raw EXIF data from the platform
+   * Normalized Exif tags
    */
   tags?: ExifTags
 }