diff --git a/pw_bluetooth_sapphire/public/pw_bluetooth_sapphire/internal/host/transport/slab_allocators.h b/pw_bluetooth_sapphire/public/pw_bluetooth_sapphire/internal/host/transport/slab_allocators.h
index d35bc8e8d9..6788dea4ec 100644
--- a/pw_bluetooth_sapphire/public/pw_bluetooth_sapphire/internal/host/transport/slab_allocators.h
+++ b/pw_bluetooth_sapphire/public/pw_bluetooth_sapphire/internal/host/transport/slab_allocators.h
@@ -13,6 +13,9 @@
 // the License.
 
 #pragma once
+#include <pw_bluetooth/hci_common.emb.h>
+#include <pw_bluetooth/hci_data.emb.h>
+
 #include <memory>
 
 #include "pw_bluetooth_sapphire/internal/host/common/macros.h"
@@ -35,26 +38,30 @@ constexpr size_t kMaxNumSlabs = 100;
 // The largest possible control packet size.
 constexpr size_t kMaxEventPayloadSize = hci_spec::kMaxEventPacketPayloadSize;
 constexpr size_t kMaxEventPacketSize =
-    sizeof(hci_spec::EventHeader) + kMaxEventPayloadSize;
+    pw::bluetooth::emboss::EventHeader::IntrinsicSizeInBytes() +
+    kMaxEventPayloadSize;
 constexpr size_t kMaxNumEventPackets =
     kMaxControlSlabSize / kMaxEventPacketSize;
 
 // Large, medium, and small buffer sizes for ACL data packets.
 constexpr size_t kLargeACLDataPayloadSize = hci_spec::kMaxACLPayloadSize;
 constexpr size_t kLargeACLDataPacketSize =
-    sizeof(hci_spec::ACLDataHeader) + kLargeACLDataPayloadSize;
+    pw::bluetooth::emboss::AclDataFrameHeader::IntrinsicSizeInBytes() +
+    kLargeACLDataPayloadSize;
 constexpr size_t kNumLargeACLDataPackets =
     kMaxACLSlabSize / kLargeACLDataPacketSize;
 
 constexpr size_t kMediumACLDataPayloadSize = 256;
 constexpr size_t kMediumACLDataPacketSize =
-    sizeof(hci_spec::ACLDataHeader) + kMediumACLDataPayloadSize;
+    pw::bluetooth::emboss::AclDataFrameHeader::IntrinsicSizeInBytes() +
+    kMediumACLDataPayloadSize;
 constexpr size_t kNumMediumACLDataPackets =
     kMaxACLSlabSize / kMediumACLDataPacketSize;
 
 constexpr size_t kSmallACLDataPayloadSize = 64;
 constexpr size_t kSmallACLDataPacketSize =
-    sizeof(hci_spec::ACLDataHeader) + kSmallACLDataPayloadSize;
+    pw::bluetooth::emboss::AclDataFrameHeader::IntrinsicSizeInBytes() +
+    kSmallACLDataPayloadSize;
 constexpr size_t kNumSmallACLDataPackets =
     kMaxACLSlabSize / kSmallACLDataPacketSize;