diff --git a/zion/include/zcall.h b/zion/include/zcall.h
index f2295a8..058295d 100644
--- a/zion/include/zcall.h
+++ b/zion/include/zcall.h
@@ -37,25 +37,23 @@ void ZThreadExit();
 
 [[nodiscard]] z_err_t ZChannelCreate(z_cap_t* channel1, z_cap_t* channel2);
 [[nodiscard]] z_err_t ZChannelSend(z_cap_t chan_cap, uint64_t num_bytes,
-                                   const uint8_t* bytes, uint64_t num_caps,
+                                   const void* data, uint64_t num_caps,
                                    const z_cap_t* caps);
 [[nodiscard]] z_err_t ZChannelRecv(z_cap_t chan_cap, uint64_t num_bytes,
-                                   uint8_t* bytes, uint64_t num_caps,
-                                   z_cap_t* caps, uint64_t* actual_bytes,
+                                   void* data, uint64_t num_caps, z_cap_t* caps,
+                                   uint64_t* actual_bytes,
                                    uint64_t* actual_caps);
 
 [[nodiscard]] z_err_t ZPortCreate(z_cap_t* port_cap);
 [[nodiscard]] z_err_t ZPortSend(z_cap_t port_cap, uint64_t num_bytes,
-                                const uint8_t* bytes, uint64_t num_caps,
+                                const void* data, uint64_t num_caps,
                                 z_cap_t* caps);
 [[nodiscard]] z_err_t ZPortRecv(z_cap_t port_cap, uint64_t num_bytes,
-                                uint8_t* bytes, uint64_t num_caps,
-                                z_cap_t* caps, uint64_t* actual_bytes,
-                                uint64_t* actual_caps);
+                                void* data, uint64_t num_caps, z_cap_t* caps,
+                                uint64_t* actual_bytes, uint64_t* actual_caps);
 [[nodiscard]] z_err_t ZPortPoll(z_cap_t port_cap, uint64_t num_bytes,
-                                uint8_t* bytes, uint64_t num_caps,
-                                z_cap_t* caps, uint64_t* actual_bytes,
-                                uint64_t* actual_caps);
+                                void* data, uint64_t num_caps, z_cap_t* caps,
+                                uint64_t* actual_bytes, uint64_t* actual_caps);
 [[nodiscard]] z_err_t ZIrqRegister(uint64_t irq_num, z_cap_t* port_cap);
 
 [[nodiscard]] z_err_t ZCapDuplicate(z_cap_t cap_in, z_cap_t* cap_out);
diff --git a/zion/object/channel.cpp b/zion/object/channel.cpp
index d1365a9..8736d42 100644
--- a/zion/object/channel.cpp
+++ b/zion/object/channel.cpp
@@ -37,7 +37,7 @@ z_err_t Channel::Read(ZMessage& msg) {
   msg.num_bytes = next_msg->num_bytes;
 
   for (uint64_t i = 0; i < msg.num_bytes; i++) {
-    msg.bytes[i] = next_msg->bytes[i];
+    static_cast<uint8_t*>(msg.data)[i] = next_msg->bytes[i];
   }
 
   msg.num_caps = next_msg->caps.size();
@@ -63,7 +63,7 @@ z_err_t Channel::EnqueueMessage(const ZMessage& msg) {
   message->num_bytes = msg.num_bytes;
   message->bytes = new uint8_t[msg.num_bytes];
   for (uint64_t i = 0; i < msg.num_bytes; i++) {
-    message->bytes[i] = msg.bytes[i];
+    message->bytes[i] = static_cast<uint8_t*>(msg.data)[i];
   }
 
   // Release and store capabilities.
diff --git a/zion/object/port.cpp b/zion/object/port.cpp
index cdc3b22..c8440d3 100644
--- a/zion/object/port.cpp
+++ b/zion/object/port.cpp
@@ -14,7 +14,7 @@ z_err_t Port::Write(const ZMessage& msg) {
   message->num_bytes = msg.num_bytes;
   message->bytes = new uint8_t[msg.num_bytes];
   for (uint64_t i = 0; i < msg.num_bytes; i++) {
-    message->bytes[i] = msg.bytes[i];
+    message->bytes[i] = static_cast<uint8_t*>(msg.data)[i];
   }
 
   for (uint64_t i = 0; i < msg.num_caps; i++) {
@@ -57,7 +57,7 @@ z_err_t Port::Read(ZMessage& msg) {
   msg.num_bytes = next_msg->num_bytes;
 
   for (uint64_t i = 0; i < msg.num_bytes; i++) {
-    msg.bytes[i] = next_msg->bytes[i];
+    static_cast<uint8_t*>(msg.data)[i] = next_msg->bytes[i];
   }
 
   msg.num_caps = next_msg->caps.size();
diff --git a/zion/usr/zcall.cpp b/zion/usr/zcall.cpp
index e871cbc..342b286 100644
--- a/zion/usr/zcall.cpp
+++ b/zion/usr/zcall.cpp
@@ -125,14 +125,14 @@ z_err_t ZChannelCreate(z_cap_t* channel1, z_cap_t* channel2) {
   return ret;
 }
 
-z_err_t ZChannelSend(z_cap_t chan_cap, uint64_t num_bytes, const uint8_t* bytes,
+z_err_t ZChannelSend(z_cap_t chan_cap, uint64_t num_bytes, const void* data,
                      uint64_t num_caps, const z_cap_t* caps) {
   ZChannelSendReq req{
       .chan_cap = chan_cap,
       .message =
           {
               .num_bytes = num_bytes,
-              .bytes = const_cast<uint8_t*>(bytes),
+              .data = const_cast<void*>(data),
               .num_caps = num_caps,
               .caps = const_cast<z_cap_t*>(caps),
           },
@@ -140,7 +140,7 @@ z_err_t ZChannelSend(z_cap_t chan_cap, uint64_t num_bytes, const uint8_t* bytes,
   return SysCall1(Z_CHANNEL_SEND, &req);
 }
 
-z_err_t ZChannelRecv(z_cap_t chan_cap, uint64_t num_bytes, uint8_t* bytes,
+z_err_t ZChannelRecv(z_cap_t chan_cap, uint64_t num_bytes, void* data,
                      uint64_t num_caps, z_cap_t* caps, uint64_t* actual_bytes,
                      uint64_t* actual_caps) {
   ZChannelRecvReq req{
@@ -148,7 +148,7 @@ z_err_t ZChannelRecv(z_cap_t chan_cap, uint64_t num_bytes, uint8_t* bytes,
       .message =
           {
               .num_bytes = num_bytes,
-              .bytes = bytes,
+              .data = data,
               .num_caps = num_caps,
               .caps = caps,
           },
@@ -166,19 +166,19 @@ z_err_t ZPortCreate(z_cap_t* port_cap) {
   return ret;
 }
 
-z_err_t ZPortSend(z_cap_t port_cap, uint64_t num_bytes, const uint8_t* bytes,
+z_err_t ZPortSend(z_cap_t port_cap, uint64_t num_bytes, const void* data,
                   uint64_t num_caps, z_cap_t* caps) {
   ZPortSendReq req{.port_cap = port_cap,
                    .message = {
                        .num_bytes = num_bytes,
-                       .bytes = const_cast<uint8_t*>(bytes),
+                       .data = const_cast<void*>(data),
                        .num_caps = num_caps,
                        .caps = caps,
                    }};
   return SysCall1(Z_PORT_SEND, &req);
 }
 
-z_err_t ZPortRecv(z_cap_t port_cap, uint64_t num_bytes, uint8_t* bytes,
+z_err_t ZPortRecv(z_cap_t port_cap, uint64_t num_bytes, void* data,
                   uint64_t num_caps, z_cap_t* caps, uint64_t* actual_bytes,
                   uint64_t* actual_caps) {
   ZPortRecvReq req{
@@ -186,7 +186,7 @@ z_err_t ZPortRecv(z_cap_t port_cap, uint64_t num_bytes, uint8_t* bytes,
       .message =
           {
               .num_bytes = num_bytes,
-              .bytes = bytes,
+              .data = data,
               .num_caps = num_caps,
               .caps = caps,
           },
@@ -197,7 +197,7 @@ z_err_t ZPortRecv(z_cap_t port_cap, uint64_t num_bytes, uint8_t* bytes,
   return ret;
 }
 
-z_err_t ZPortPoll(z_cap_t port_cap, uint64_t num_bytes, uint8_t* bytes,
+z_err_t ZPortPoll(z_cap_t port_cap, uint64_t num_bytes, void* data,
                   uint64_t num_caps, z_cap_t* caps, uint64_t* actual_bytes,
                   uint64_t* actual_caps) {
   ZPortRecvReq req{
@@ -205,7 +205,7 @@ z_err_t ZPortPoll(z_cap_t port_cap, uint64_t num_bytes, uint8_t* bytes,
       .message =
           {
               .num_bytes = num_bytes,
-              .bytes = bytes,
+              .data = data,
               .num_caps = num_caps,
               .caps = caps,
           },
diff --git a/zion/usr/zcall_internal.h b/zion/usr/zcall_internal.h
index 105bbb3..556a0db 100644
--- a/zion/usr/zcall_internal.h
+++ b/zion/usr/zcall_internal.h
@@ -70,7 +70,7 @@ struct ZChannelCreateResp {
 
 struct ZMessage {
   uint64_t num_bytes;
-  uint8_t* bytes;
+  void* data;
 
   uint64_t num_caps;
   z_cap_t* caps;