diff --git a/kernel/system.c b/kernel/system.c
index feafef001..410c40393 100755
--- a/kernel/system.c
+++ b/kernel/system.c
@@ -75,8 +75,7 @@ PUBLIC void sys_task()
       caller_ptr = proc_addr(m.m_source);	
 
       /* See if the caller made a valid request and try to handle it. */
-      if (! (priv(caller_ptr)->s_call_mask & (1<<call_nr)) &&
-	  m.m_type != SYS_IOPENABLE ) {
+      if (! (priv(caller_ptr)->s_call_mask & (1<<call_nr))) {
 #if DEBUG_ENABLE_IPC_WARNINGS
 	  kprintf("SYSTEM: request %d from %d denied.\n", call_nr,m.m_source);
 #endif
diff --git a/kernel/table.c b/kernel/table.c
index dbc40e64d..c145b3e3e 100755
--- a/kernel/table.c
+++ b/kernel/table.c
@@ -83,7 +83,8 @@ PUBLIC char *t_stack[TOT_STACK_SPACE / sizeof(char *)];
 #define FS_C	(c(SYS_KILL) | c(SYS_VIRCOPY) | c(SYS_VIRVCOPY) | c(SYS_UMAP) | c(SYS_GETINFO) | c(SYS_EXIT) | c(SYS_TIMES) | c(SYS_SETALARM))
 #define DRV_C	(FS_C | c(SYS_SEGCTL) | c(SYS_IRQCTL) | c(SYS_INT86) | c(SYS_DEVIO) | c(SYS_VDEVIO) | c(SYS_SDEVIO)) 
 #define TTY_C (DRV_C | c(SYS_ABORT))
-#define MEM_C	(DRV_C | c(SYS_PHYSCOPY) | c(SYS_PHYSVCOPY) | c(SYS_VM_MAP))
+#define MEM_C	(DRV_C | c(SYS_PHYSCOPY) | c(SYS_PHYSVCOPY) | c(SYS_VM_MAP) | \
+	c(SYS_IOPENABLE))
 
 /* The system image table lists all programs that are part of the boot image. 
  * The order of the entries here MUST agree with the order of the programs