diff --git a/libraries/AP_RPM/RPM_DroneCAN.cpp b/libraries/AP_RPM/RPM_DroneCAN.cpp
index 4657ff7714..fffc87c0b1 100644
--- a/libraries/AP_RPM/RPM_DroneCAN.cpp
+++ b/libraries/AP_RPM/RPM_DroneCAN.cpp
@@ -34,15 +34,11 @@ AP_RPM_DroneCAN::AP_RPM_DroneCAN(AP_RPM &_ap_rpm, uint8_t instance, AP_RPM::RPM_
 }
 
 // Subscribe to incoming rpm messages
-void AP_RPM_DroneCAN::subscribe_msgs(AP_DroneCAN* ap_dronecan)
+bool AP_RPM_DroneCAN::subscribe_msgs(AP_DroneCAN* ap_dronecan)
 {
-    if (ap_dronecan == nullptr) {
-        return;
-    }
+    const auto driver_index = ap_dronecan->get_driver_index();
 
-    if (Canard::allocate_sub_arg_callback(ap_dronecan, &handle_rpm, ap_dronecan->get_driver_index()) == nullptr) {
-        AP_BoardConfig::allocation_error("rpm_sub");
-    }
+    return (Canard::allocate_sub_arg_callback(ap_dronecan, &handle_rpm, driver_index) != nullptr);
 }
 
 // Receive new CAN message
diff --git a/libraries/AP_RPM/RPM_DroneCAN.h b/libraries/AP_RPM/RPM_DroneCAN.h
index c9d8e8c0c5..ae69240713 100644
--- a/libraries/AP_RPM/RPM_DroneCAN.h
+++ b/libraries/AP_RPM/RPM_DroneCAN.h
@@ -27,7 +27,7 @@ public:
     AP_RPM_DroneCAN(AP_RPM &_ap_rpm, uint8_t instance, AP_RPM::RPM_State &_state);
 
     // Subscribe to incoming rpm messages
-    static void subscribe_msgs(AP_DroneCAN* ap_dronecan);
+    static bool subscribe_msgs(AP_DroneCAN* ap_dronecan);
 
     // update state
     void update(void) override;