diff --git a/harness/native-compressor.harness.ts b/harness/native-compressor.harness.ts
index 4cd89a2..32e39a3 100644
--- a/harness/native-compressor.harness.ts
+++ b/harness/native-compressor.harness.ts
@@ -133,6 +133,9 @@ describe('react-native-compressor native harness', () => {
     const metadata = await getImageMetaData(output);
     expect(metadata.ImageWidth).toBeGreaterThan(0);
     expect(metadata.ImageHeight).toBeGreaterThan(0);
+    // the fixture is 16×16, so maxWidth/maxHeight must shrink it (#417)
+    expect(metadata.ImageWidth).toBeLessThanOrEqual(8);
+    expect(metadata.ImageHeight).toBeLessThanOrEqual(8);
     expect(metadata.size).toBeGreaterThan(0);
     expect(metadata.exif).toBeTruthy();
 
diff --git a/ios/Image/ImageCompressorOptions.swift b/ios/Image/ImageCompressorOptions.swift
index d45b88d..ded6951 100644
--- a/ios/Image/ImageCompressorOptions.swift
+++ b/ios/Image/ImageCompressorOptions.swift
@@ -28,14 +28,18 @@ class ImageCompressorOptions: NSObject {
             switch key {
             case "compressionMethod":
                 options.autoCompress = (value as? String ?? "") != "manual"
+            // Nitro hands every JS number over as a Swift Double, which `as? Int` and
+            // `as? Float` never match, so these options silently fell back to their
+            // defaults (#417). NSNumber bridges a Double, an Int and an NSNumber alike,
+            // the same cast VideoMain uses for its numeric options.
             case "maxWidth":
-                options.maxWidth = (value as? Int) ?? 1280
+                options.maxWidth = (value as? NSNumber)?.intValue ?? 1280
             case "maxHeight":
-                options.maxHeight = (value as? Int) ?? 1280
+                options.maxHeight = (value as? NSNumber)?.intValue ?? 1280
             case "progressDivider":
-                options.progressDivider = (value as? Int) ?? 0
+                options.progressDivider = (value as? NSNumber)?.intValue ?? 0
             case "quality":
-                options.quality = (value as? Float) ?? 0.8
+                options.quality = (value as? NSNumber)?.floatValue ?? 0.8
             case "input":
                 options.parseInput(value as? String)
             case "output":