diff --git a/libuavcan_drivers/stm32/driver/src/uc_stm32_can.cpp b/libuavcan_drivers/stm32/driver/src/uc_stm32_can.cpp
index 13cef40aad..5bb5cf199d 100644
--- a/libuavcan_drivers/stm32/driver/src/uc_stm32_can.cpp
+++ b/libuavcan_drivers/stm32/driver/src/uc_stm32_can.cpp
@@ -472,7 +472,8 @@ uavcan::int16_t CanIface::configureFilters(const uavcan::CanFilterConfig* filter
         {
             can_->FilterRegister[filter_start_index].FR1 = 0;
             can_->FilterRegister[filter_start_index].FR2 = 0;
-            can_->FA1R = 1 << filter_start_index;
+            // We can't directly overwrite FA1R because that breaks the other CAN interface
+            can_->FA1R |= 1U << filter_start_index;              // Other filters may still be enabled, we don't care
         }
         else
         {