Index: uspace/app/msim/arch_helenos/input.c
===================================================================
--- uspace/app/msim/arch_helenos/input.c	(revision f8cbe2c319e3f91e545d3d2749a8c2a1348c1a65)
+++ uspace/app/msim/arch_helenos/input.c	(revision b5c2f5646cd6ac5e55c6a21110f700bb5fb3bae1)
@@ -32,4 +32,7 @@
 /** @file HelenOS specific functions for MSIM simulator.
  */
+
+/* Because of asprintf. */
+#define _GNU_SOURCE
 #include "../../io/input.h"
 #include "../../io/output.h"