diff --git a/arch/arm/mach-iop13xx/setup.c b/arch/arm/mach-iop13xx/setup.c
index 3756d2ccb1a7..5fbeb28d04bb 100644
--- a/arch/arm/mach-iop13xx/setup.c
+++ b/arch/arm/mach-iop13xx/setup.c
@@ -337,7 +337,7 @@ void __init iop13xx_platform_init(void)
 
 #ifdef CONFIG_MTD_PHYSMAP
 	iq8134x_flash_resource.end = iq8134x_flash_resource.start +
-				iq8134x_probe_flash_size();
+				iq8134x_probe_flash_size() - 1;
 	if (iq8134x_flash_resource.end > iq8134x_flash_resource.start)
 		iop13xx_devices[plat_idx++] = &iq8134x_flash;
 	else