diff --git a/include/plat/spike/plat/machine/hardware.h b/include/plat/spike/plat/machine/hardware.h
index 0c6968411..b7c1930ac 100644
--- a/include/plat/spike/plat/machine/hardware.h
+++ b/include/plat/spike/plat/machine/hardware.h
@@ -60,7 +60,7 @@
 #ifndef __ASSEMBLER__
 
 int get_num_avail_p_regs(void);
-p_region_t get_avail_p_reg(unsigned int i);
+p_region_t get_avail_p_reg(word_t i);
 bool_t add_avail_p_reg(p_region_t reg);
 void map_kernel_devices(void);
 
diff --git a/src/plat/spike/machine/hardware.c b/src/plat/spike/machine/hardware.c
index 10cdc9e84..86e85c9c8 100644
--- a/src/plat/spike/machine/hardware.c
+++ b/src/plat/spike/machine/hardware.c
@@ -51,7 +51,7 @@ BOOT_CODE int get_num_avail_p_regs(void)
     return sizeof(avail_p_regs) / sizeof(p_region_t);
 }
 
-BOOT_CODE p_region_t get_avail_p_reg(unsigned int i)
+BOOT_CODE p_region_t get_avail_p_reg(word_t i)
 {
     return avail_p_regs[i];
 }