diff --git a/pw_bluetooth_sapphire/host/gap/adapter.cc b/pw_bluetooth_sapphire/host/gap/adapter.cc
index 8b6ffa24c3..4b9b2f0f01 100644
--- a/pw_bluetooth_sapphire/host/gap/adapter.cc
+++ b/pw_bluetooth_sapphire/host/gap/adapter.cc
@@ -1123,18 +1123,19 @@ void AdapterImpl::InitializeStep2() {
       hci::EmbossCommandPacket::New<
           pw::bluetooth::emboss::LEReadSupportedStatesCommandView>(
           hci_spec::kLEReadSupportedStates),
-      [this](const hci::EventPacket& cmd_complete) {
+      [this](const hci::EmbossEventPacket& cmd_complete) {
         if (hci_is_error(cmd_complete,
                          WARN,
                          "gap",
                          "LE read local supported states failed")) {
           return;
         }
-        auto params =
+        auto packet =
             cmd_complete
-                .return_params<hci_spec::LEReadSupportedStatesReturnParams>();
-        state_.low_energy_state.supported_states_ = pw::bytes::ConvertOrderFrom(
-            cpp20::endian::little, params->le_states);
+                .view<pw::bluetooth::emboss::
+                          LEReadSupportedStatesCommandCompleteEventView>();
+        state_.low_energy_state.supported_states_ =
+            packet.le_states().BackingStorage().ReadLittleEndianUInt<64>();
       });
 
   if (state_.SupportedCommands()
diff --git a/pw_bluetooth_sapphire/host/testing/fake_controller.cc b/pw_bluetooth_sapphire/host/testing/fake_controller.cc
index 67026a83b6..2def21badc 100644
--- a/pw_bluetooth_sapphire/host/testing/fake_controller.cc
+++ b/pw_bluetooth_sapphire/host/testing/fake_controller.cc
@@ -1662,12 +1662,14 @@ void FakeController::OnLEReadBufferSizeV2() {
 }
 
 void FakeController::OnLEReadSupportedStates() {
-  hci_spec::LEReadSupportedStatesReturnParams params;
-  params.status = pwemb::StatusCode::SUCCESS;
-  params.le_states = pw::bytes::ConvertOrderTo(cpp20::endian::little,
-                                               settings_.le_supported_states);
-  RespondWithCommandComplete(hci_spec::kLEReadSupportedStates,
-                             BufferView(&params, sizeof(params)));
+  auto packet = hci::EmbossEventPacket::New<
+      pwemb::LEReadSupportedStatesCommandCompleteEventWriter>(
+      hci_spec::kCommandCompleteEventCode);
+  auto view = packet.view_t();
+  view.status().Write(pwemb::StatusCode::SUCCESS);
+  view.le_states().BackingStorage().WriteLittleEndianUInt<64>(
+      settings_.le_supported_states);
+  RespondWithCommandComplete(pwemb::OpCode::LE_READ_SUPPORTED_STATES, &packet);
 }
 
 void FakeController::OnLEReadLocalSupportedFeatures() {
diff --git a/pw_bluetooth_sapphire/public/pw_bluetooth_sapphire/internal/host/hci-spec/protocol.h b/pw_bluetooth_sapphire/public/pw_bluetooth_sapphire/internal/host/hci-spec/protocol.h
index 0c8664dbf7..4bbf725389 100644
--- a/pw_bluetooth_sapphire/public/pw_bluetooth_sapphire/internal/host/hci-spec/protocol.h
+++ b/pw_bluetooth_sapphire/public/pw_bluetooth_sapphire/internal/host/hci-spec/protocol.h
@@ -947,15 +947,6 @@ constexpr OpCode kLELongTermKeyRequestNegativeReply =
 // LE Read Supported States Command (v4.0) (LE)
 constexpr OpCode kLEReadSupportedStates = LEControllerCommandOpCode(0x001C);
 
-struct LEReadSupportedStatesReturnParams {
-  // See enum StatusCode in hci_constants.h.
-  StatusCode status;
-
-  // Bit-mask of supported state or state combinations. See Core Spec v4.2,
-  // Volume 2, Part E, Section 7.8.27 "LE Read Supported States Command".
-  uint64_t le_states;
-} __attribute__((packed));
-
 // ====================================
 // LE Receiver Test Command (v4.0) (LE)
 constexpr OpCode kLEReceiverTest = LEControllerCommandOpCode(0x001D);