diff --git a/shell/platform/android/android_external_texture_gl.cc b/shell/platform/android/android_external_texture_gl.cc
index 0acd0c8337d25f14da5fa8374644f5befee9fa04..935f60b455797b5d8444a740c9635146b80bd5e4 100644
--- a/shell/platform/android/android_external_texture_gl.cc
+++ b/shell/platform/android/android_external_texture_gl.cc
@@ -68,6 +68,18 @@ void AndroidExternalTextureGL::Paint(SkCanvas& canvas,
   }
 }
 
+// The bounds we set for the canvas are post composition.
+// To fill the canvas we need to ensure that the transformation matrix
+// on the `SurfaceTexture` will be scaled to fill. We rescale and preseve
+// the scaled aspect ratio.
+SkSize ScaleToFill(float scaleX, float scaleY) {
+  const double epsilon = std::numeric_limits<double>::epsilon();
+  // scaleY is negative.
+  const double minScale = fmin(scaleX, fabs(scaleY));
+  const double rescale = 1.0f / (minScale + epsilon);
+  return SkSize::Make(scaleX * rescale, scaleY * rescale);
+}
+
 void AndroidExternalTextureGL::UpdateTransform() {
   JNIEnv* env = fml::jni::AttachCurrentThread();
   fml::jni::ScopedJavaLocalRef<jobject> surfaceTexture =
@@ -77,10 +89,12 @@ void AndroidExternalTextureGL::UpdateTransform() {
   SurfaceTextureGetTransformMatrix(env, surfaceTexture.obj(),
                                    transformMatrix.obj());
   float* m = env->GetFloatArrayElements(transformMatrix.obj(), nullptr);
+  float scaleX = m[0], scaleY = m[5];
+  const SkSize scaled = ScaleToFill(scaleX, scaleY);
   SkScalar matrix3[] = {
-      m[0], m[1], m[2],   //
-      m[4], m[5], m[6],   //
-      m[8], m[9], m[10],  //
+      scaled.fWidth, m[1],           m[2],   //
+      m[4],          scaled.fHeight, m[6],   //
+      m[8],          m[9],           m[10],  //
   };
   env->ReleaseFloatArrayElements(transformMatrix.obj(), m, JNI_ABORT);
   transform.set9(matrix3);