diff --git a/src/devices/keyboard-joypad/KeyboardJoypad.cpp b/src/devices/keyboard-joypad/KeyboardJoypad.cpp
index 3d71cda..ab0f128 100644
--- a/src/devices/keyboard-joypad/KeyboardJoypad.cpp
+++ b/src/devices/keyboard-joypad/KeyboardJoypad.cpp
@@ -415,6 +415,11 @@ class yarp::dev::KeyboardJoypad::Impl
                 col = 0;
             }
             newButton.col = col++;
+            if (buttons.first.back().find(alias) != buttons.first.back().end())
+            {
+                yCError(KEYBOARDJOYPAD) << "The alias" << alias << "is already present in the buttons list in the same row.";
+                return false;
+            }
             buttons.first.back()[alias] = newButton;
 
         }