diff --git a/hw/xfree86/int10/helper_exec.c b/hw/xfree86/int10/helper_exec.c
index 97ed75758..4ffd74b39 100644
--- a/hw/xfree86/int10/helper_exec.c
+++ b/hw/xfree86/int10/helper_exec.c
@@ -576,7 +576,7 @@ pciCfg1outb(CARD16 addr, CARD8 val)
 }
 
 CARD8
-bios_checksum(CARD8 *start, int size)
+bios_checksum(const CARD8 *start, int size)
 {
     CARD8 sum = 0;
 
diff --git a/hw/xfree86/int10/helper_mem.c b/hw/xfree86/int10/helper_mem.c
index 0338a86de..b84571302 100644
--- a/hw/xfree86/int10/helper_mem.c
+++ b/hw/xfree86/int10/helper_mem.c
@@ -224,7 +224,7 @@ xf86HandleInt10Options(ScrnInfoPtr pScrn, int entityIndex)
 }
 
 Bool
-int10skip(void* options)
+int10skip(const void* options)
 {
     Bool noint10 = FALSE;
 
@@ -235,7 +235,7 @@ int10skip(void* options)
 }
 
 Bool
-int10_check_bios(int scrnIndex, int codeSeg, unsigned char* vbiosMem)
+int10_check_bios(int scrnIndex, int codeSeg, const unsigned char* vbiosMem)
 {
     int size;
 
@@ -262,7 +262,7 @@ int10_check_bios(int scrnIndex, int codeSeg, unsigned char* vbiosMem)
 }
 
 Bool
-initPrimary(void* options)
+initPrimary(const void* options)
 {
     Bool initPrimary = FALSE;
 
@@ -281,7 +281,7 @@ initPrimary(void* options)
  * be used with extreme care.
  */
 void
-xf86int10ParseBiosLocation(void* options, 
+xf86int10ParseBiosLocation(const void* options,
 			   xf86int10BiosLocationPtr bios)
 {
     const char *p;
diff --git a/hw/xfree86/int10/xf86int10.h b/hw/xfree86/int10/xf86int10.h
index 581a3bdb0..47f965d74 100644
--- a/hw/xfree86/int10/xf86int10.h
+++ b/hw/xfree86/int10/xf86int10.h
@@ -143,7 +143,7 @@ void dump_code(xf86Int10InfoPtr pInt);
 void dump_registers(xf86Int10InfoPtr pInt);
 void stack_trace(xf86Int10InfoPtr pInt);
 xf86Int10InfoPtr getInt10Rec(int entityIndex);
-CARD8 bios_checksum(CARD8 *start, int size);
+CARD8 bios_checksum(const CARD8 *start, int size);
 void LockLegacyVGA(xf86Int10InfoPtr pInt, legacyVGAPtr vga);
 void UnlockLegacyVGA(xf86Int10InfoPtr pInt, legacyVGAPtr vga);
 #if defined (_PC)
@@ -182,10 +182,11 @@ int setup_system_bios(void *base_addr);
 void reset_int_vect(xf86Int10InfoPtr pInt);
 void set_return_trap(xf86Int10InfoPtr pInt);
 void * xf86HandleInt10Options(ScrnInfoPtr pScrn, int entityIndex);
-Bool int10skip(void* options);
-Bool int10_check_bios(int scrnIndex, int codeSeg, unsigned char* vbiosMem);
-Bool initPrimary(void* options);
-void xf86int10ParseBiosLocation(void* options, 
+Bool int10skip(const void* options);
+Bool int10_check_bios(int scrnIndex, int codeSeg,
+    const unsigned char* vbiosMem);
+Bool initPrimary(const void* options);
+void xf86int10ParseBiosLocation(const void* options, 
 				xf86int10BiosLocationPtr bios);
 BusType xf86int10GetBiosLocationType(const xf86Int10InfoPtr pInt,
     const xf86int10BiosLocationPtr bios);