diff --git a/src/superio/sis/950/superio.c b/src/superio/sis/950/superio.c
index 6ee98dfc27..1d5cf952db 100644
--- a/src/superio/sis/950/superio.c
+++ b/src/superio/sis/950/superio.c
@@ -8,20 +8,20 @@
 void
 enter_pnp()
 {
-    // unlock it XXX make this a subr at some point 
-    outb(0x87, 0x2e);
-    outb(0x01, 0x2e);
-    outb(0x55, 0x2e);
-    outb(0x55, 0x2e);
+	// unlock it XXX make this a subr at some point 
+	outb(0x87, 0x2e);
+	outb(0x01, 0x2e);
+	outb(0x55, 0x2e);
+	outb(0x55, 0x2e);
 }
 
 void
 exit_pnp()
 {
-    /* all done. */
-    // select configure control
-    outb(2, 0x2e);
-    outb(2, 0x2f);
+	/* all done. */
+	// select configure control
+	outb(2, 0x2e);
+	outb(2, 0x2f);
 }
 
 #ifdef MUST_ENABLE_FLOPPY
@@ -35,13 +35,13 @@ void enable_floppy()
 	/* now select register 0x30, and set bit 1 in that register */
 	outb(0x30, 0x2e);
 	outb(0x1, 0x2f);
-
 }
 #endif /* MUST_ENABLE_FLOPPY */
 
 void
 enable_com(int com)
 {
+    unsigned char b;
     /* now set the LDN to com LDN */
     outb(0x7, 0x2e);	/* pick reg. 7 */
     outb(com, 0x2f);	/* LDN 0 to reg. 7 */
@@ -50,6 +50,11 @@ enable_com(int com)
     outb(0x30, 0x2e);
     outb(0x1, 0x2f);
 
+    /* set CLKIN frequence to 24 MHZ */
+    outb(0x24, 0x2e);
+    b = inb(0x2f) | 0xfd;
+    outb(0x24, 0x2e);
+    outb(b, 0x2f);
 }
 
 void