diff --git a/common/os_calls.c b/common/os_calls.c
index 4269faba..3a798c46 100644
--- a/common/os_calls.c
+++ b/common/os_calls.c
@@ -896,6 +896,20 @@ g_execlp11(char* a1, char* a2, char* a3, char* a4, char* a5, char* a6,
 #endif
 }
 
+/*****************************************************************************/
+int
+g_execlp13(char* a1, char* a2, char* a3, char* a4, char* a5, char* a6,
+           char* a7, char* a8, char* a9, char* a10, char* a11,
+           char* a12, char* a13)
+{
+#if defined(_WIN32)
+  return 0;
+#else
+  return execlp(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11,
+                a12, a13, (void*)0);
+#endif
+}
+
 /*****************************************************************************/
 void
 g_signal(int sig_num, void (*func)(int))
diff --git a/common/os_calls.h b/common/os_calls.h
index b28dc4ea..52d958ee 100644
--- a/common/os_calls.h
+++ b/common/os_calls.h
@@ -146,6 +146,10 @@ g_execlp3(char* a1, char* a2, char* a3);
 int
 g_execlp11(char* a1, char* a2, char* a3, char* a4, char* a5, char* a6,
            char* a7, char* a8, char* a9, char* a10, char* a11);
+int
+g_execlp13(char* a1, char* a2, char* a3, char* a4, char* a5, char* a6,
+           char* a7, char* a8, char* a9, char* a10, char* a11,
+           char* a12, char* a13);
 void
 g_signal(int sig_num, void (*func)(int));
 void
diff --git a/sesman/session.c b/sesman/session.c
index fa7b15b2..f368e71b 100644
--- a/sesman/session.c
+++ b/sesman/session.c
@@ -230,13 +230,14 @@ for user %s denied", username);
         env_check_password_file(passwd_file, password);
         if (type == SESMAN_SESSION_TYPE_XVNC)
         {
-          g_execlp11("Xvnc", "Xvnc", screen, "-geometry", geometry,
-                     "-depth", depth, "-bs", "-rfbauth", passwd_file, 0);
+          g_execlp13("Xvnc", "Xvnc", screen, "-geometry", geometry,
+                     "-depth", depth, "-bs", "-ac", "-rfbauth", passwd_file,
+                     0, 0);
         }
         else if (type == SESMAN_SESSION_TYPE_XRDP)
         {
           g_execlp11("Xrdp", "Xrdp", screen, "-geometry", geometry,
-                     "-depth", depth, "-bs", 0, 0, 0);
+                     "-depth", depth, "-bs", "-ac", 0, 0);
         }
         else
         {