diff --git a/libraries/AP_HAL_ChibiOS/CANFDIface.cpp b/libraries/AP_HAL_ChibiOS/CANFDIface.cpp
index 2d261f7242084c..a0f8e28192a7fe 100644
--- a/libraries/AP_HAL_ChibiOS/CANFDIface.cpp
+++ b/libraries/AP_HAL_ChibiOS/CANFDIface.cpp
@@ -85,7 +85,7 @@
 #error "Unsupported MCU for FDCAN"
 #endif
 
-extern AP_HAL::HAL& hal;
+extern const AP_HAL::HAL& hal;
 
 #define STR(x) #x
 #define XSTR(x) STR(x)
@@ -568,7 +568,7 @@ bool CANIface::init(const uint32_t bitrate, const uint32_t fdbitrate, const Oper
     if (can_ifaces[self_index_] == nullptr) {
         can_ifaces[self_index_] = this;
 #if !defined(HAL_BOOTLOADER_BUILD)
-        hal.can[self_index_] = this;
+        const_cast <AP_HAL::HAL&> (hal).can[self_index_] = this;
 #endif
     }
 
diff --git a/libraries/AP_HAL_ChibiOS/CanIface.cpp b/libraries/AP_HAL_ChibiOS/CanIface.cpp
index 677f484804943e..2ad28509ccac1c 100644
--- a/libraries/AP_HAL_ChibiOS/CanIface.cpp
+++ b/libraries/AP_HAL_ChibiOS/CanIface.cpp
@@ -84,7 +84,7 @@
 #endif
 
 
-extern AP_HAL::HAL& hal;
+extern const AP_HAL::HAL& hal;
 
 using namespace ChibiOS;
 
@@ -846,7 +846,7 @@ bool CANIface::init(const uint32_t bitrate, const CANIface::OperatingMode mode)
     if (can_ifaces[self_index_] == nullptr) {
         can_ifaces[self_index_] = this;
 #if !defined(HAL_BOOTLOADER_BUILD)
-        hal.can[self_index_] = this;
+        const_cast <AP_HAL::HAL&> (hal).can[self_index_] = this;
 #endif
     }