diff --git a/hal/src/main/native/systemcore/CAN.cpp b/hal/src/main/native/systemcore/CAN.cpp
index 3837440ac9..a7956f4e61 100644
--- a/hal/src/main/native/systemcore/CAN.cpp
+++ b/hal/src/main/native/systemcore/CAN.cpp
@@ -166,7 +166,14 @@ bool SocketCanState::InitializeBuses() {
       }
 
       ifreq ifr;
-      std::snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "can_s%d", i);
+
+      if (i < 5) {
+        std::snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "can_s%u",
+                      static_cast<unsigned>(i));
+      } else {
+        std::snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "can_d%u",
+                      static_cast<unsigned>(i - 5));
+      }
 
       if (ioctl(socketHandle[i], SIOCGIFINDEX, &ifr) == -1) {
         wpi::util::print("ioctl(SIOCGIFINDEX) for CAN {} failed with {}\n",
@@ -336,6 +343,13 @@ void HAL_CAN_SendMessage(int32_t busId, uint32_t messageId,
     return;
   }
 
+  if (busId >= 5 &&
+      ((message->flags & HAL_CANFlags::HAL_CAN_FD_DATALENGTH) ||
+       (message->flags & HAL_CANFlags::HAL_CAN_FD_BITRATESWITCH))) {
+    *status = PARAMETER_OUT_OF_RANGE;
+    return;
+  }
+
   messageId = MapMessageIdToSocketCan(messageId);
 
   // TODO determine on the real roborio is a non periodic send removes any
diff --git a/hal/src/main/native/systemcore/PortsInternal.hpp b/hal/src/main/native/systemcore/PortsInternal.hpp
index bb3439ef5a..413b97cb1c 100644
--- a/hal/src/main/native/systemcore/PortsInternal.hpp
+++ b/hal/src/main/native/systemcore/PortsInternal.hpp
@@ -8,7 +8,7 @@
 
 namespace wpi::hal {
 
-constexpr int32_t kNumCanBuses = 5;
+constexpr int32_t kNumCanBuses = 25;
 constexpr int32_t kNumSmartIo = 6;
 constexpr int32_t kNumI2cBuses = 2;
 constexpr int32_t kNumAccumulators = 0;