diff --git a/plat/arm/board/juno/aarch64/juno_helpers.S b/plat/arm/board/juno/aarch64/juno_helpers.S
index 377b0cb..9291fa4 100644
--- a/plat/arm/board/juno/aarch64/juno_helpers.S
+++ b/plat/arm/board/juno/aarch64/juno_helpers.S
@@ -206,7 +206,7 @@
 endfunc plat_reset_handler
 
 	/* -----------------------------------------------------
-	 *  unsigned int plat_arm_calc_core_pos(uint64_t mpidr)
+	 *  unsigned int plat_arm_calc_core_pos(u_register_t mpidr)
 	 *  Helper function to calculate the core position.
 	 * -----------------------------------------------------
 	 */