diff --git a/src/main.c b/src/main.c
index 299e2fb..8efc39d 100644
--- a/src/main.c
+++ b/src/main.c
@@ -34,12 +34,19 @@ int main(void)
 void Enable(void)
 {
 	USART_Printf("[CORE] Parsed 'CMD_RUN' token.\r\n");
+	if (running == true) {
+		USART_Printf("[CORE] Error: Already running.\r\n");
+	}
+
 	running = true;
 }
 
 void Disable(void)
 {
 	USART_Printf("[CORE] Parsed 'CMD_STOP' token.\r\n");
+	if (running == false) {
+		USART_Printf("[CORE] Error: Already stopped.\r\n");
+	}
 	running = false;
 }