diff --git a/libuavcan_drivers/linux/apps/test_node.cpp b/libuavcan_drivers/linux/apps/test_node.cpp
index 3ec9b0938b..2241f246ca 100644
--- a/libuavcan_drivers/linux/apps/test_node.cpp
+++ b/libuavcan_drivers/linux/apps/test_node.cpp
@@ -106,7 +106,7 @@ int main(int argc, const char** argv)
     {
         if (argc < 3)
         {
-            std::cout << "Usage:\n\t" << argv[0] << " <node-id> <can-iface-name-1> [can-iface-name-N...]" << std::endl;
+            std::cerr << "Usage:\n\t" << argv[0] << " <node-id> <can-iface-name-1> [can-iface-name-N...]" << std::endl;
             return 1;
         }
         const int self_node_id = std::stoi(argv[1]);
diff --git a/libuavcan_drivers/linux/apps/test_socket.cpp b/libuavcan_drivers/linux/apps/test_socket.cpp
index 1b37fc8c7a..5d62ad4fea 100644
--- a/libuavcan_drivers/linux/apps/test_socket.cpp
+++ b/libuavcan_drivers/linux/apps/test_socket.cpp
@@ -336,7 +336,7 @@ int main(int argc, const char** argv)
     {
         if (argc < 2)
         {
-            std::cout << "Usage:\n\t" << argv[0] << " <can-iface-name-1> [can-iface-name-N...]" << std::endl;
+            std::cerr << "Usage:\n\t" << argv[0] << " <can-iface-name-1> [can-iface-name-N...]" << std::endl;
             return 1;
         }
 
diff --git a/libuavcan_drivers/linux/apps/test_time_sync.cpp b/libuavcan_drivers/linux/apps/test_time_sync.cpp
index b85f889b48..c956a4912e 100644
--- a/libuavcan_drivers/linux/apps/test_time_sync.cpp
+++ b/libuavcan_drivers/linux/apps/test_time_sync.cpp
@@ -88,7 +88,7 @@ int main(int argc, const char** argv)
     {
         if (argc < 3)
         {
-            std::cout << "Usage:\n\t" << argv[0] << " <node-id> <can-iface-name-1> [can-iface-name-N...]" << std::endl;
+            std::cerr << "Usage:\n\t" << argv[0] << " <node-id> <can-iface-name-1> [can-iface-name-N...]" << std::endl;
             return 1;
         }
         const int self_node_id = std::stoi(argv[1]);
diff --git a/libuavcan_drivers/linux/apps/uavcan_nodetool.cpp b/libuavcan_drivers/linux/apps/uavcan_nodetool.cpp
index f40485967e..1b19fb4bb2 100644
--- a/libuavcan_drivers/linux/apps/uavcan_nodetool.cpp
+++ b/libuavcan_drivers/linux/apps/uavcan_nodetool.cpp
@@ -352,7 +352,7 @@ int main(int argc, const char** argv)
     {
         if (argc < 3)
         {
-            std::cout << "Usage:\n\t" << argv[0] << " <node-id> <can-iface-name-1> [can-iface-name-N...]" << std::endl;
+            std::cerr << "Usage:\n\t" << argv[0] << " <node-id> <can-iface-name-1> [can-iface-name-N...]" << std::endl;
             return 1;
         }
         const int self_node_id = std::stoi(argv[1]);
diff --git a/libuavcan_drivers/linux/apps/uavcan_status_monitor.cpp b/libuavcan_drivers/linux/apps/uavcan_status_monitor.cpp
index 5f3f232e3a..9672c77988 100644
--- a/libuavcan_drivers/linux/apps/uavcan_status_monitor.cpp
+++ b/libuavcan_drivers/linux/apps/uavcan_status_monitor.cpp
@@ -131,7 +131,7 @@ int main(int argc, const char** argv)
     {
         if (argc < 2)
         {
-            std::cout << "Usage:\n\t" << argv[0] << " <can-iface-name-1> [can-iface-name-N...]" << std::endl;
+            std::cerr << "Usage:\n\t" << argv[0] << " <can-iface-name-1> [can-iface-name-N...]" << std::endl;
             return 1;
         }
         std::vector<std::string> iface_names;