diff --git a/examples/ui/lib/type_converters.cc b/examples/ui/lib/type_converters.cc
index ae887a4..b7e749a 100644
--- a/examples/ui/lib/type_converters.cc
+++ b/examples/ui/lib/type_converters.cc
@@ -108,7 +108,7 @@
     const SkMatrix& input) {
   // Expand 3x3 to 4x4.
   fuchsia::math::Transform output;
-  float* m = output.matrix.mutable_data();
+  float* m = output.matrix.data();
   m[0] = input[0];
   m[1] = input[1];
   m[2] = 0.f;
@@ -138,7 +138,7 @@
 fuchsia::math::Transform TypeConverter<fuchsia::math::Transform, SkMatrix44>::Convert(
     const SkMatrix44& input) {
   fuchsia::math::Transform output;
-  input.asRowMajorf(output.matrix.mutable_data());
+  input.asRowMajorf(output.matrix.data());
   return output;
 }
 
diff --git a/runtime/flutter_runner/semantics_bridge.cc b/runtime/flutter_runner/semantics_bridge.cc
index eb72549..0427f6a 100644
--- a/runtime/flutter_runner/semantics_bridge.cc
+++ b/runtime/flutter_runner/semantics_bridge.cc
@@ -29,8 +29,8 @@
 // format to fuchsia::ui::gfx::mat4, the Fidl equivalent.
 fuchsia::ui::gfx::mat4 WrapSkMatrix(SkMatrix44& args) {
   fuchsia::ui::gfx::mat4 value;
-  DEBUG_CHECK(value.matrix.count() == 16, LOG_TAG, "");
-  float* m = value.matrix.mutable_data();
+  DEBUG_CHECK(value.matrix.size() == 16, LOG_TAG, "");
+  float* m = value.matrix.data();
   args.asColMajorf(m);
   return value;
 }