diff --git a/include/linux/dim.h b/include/linux/dim.h
index 1b581ff25a15..84579a50ae7f 100644
--- a/include/linux/dim.h
+++ b/include/linux/dim.h
@@ -351,7 +351,8 @@ void dim_park_tired(struct dim *dim);
  * Takes into consideration counter wrap-around.
  * Returned boolean indicates whether curr_stats are reliable.
  */
-bool dim_calc_stats(struct dim_sample *start, struct dim_sample *end,
+bool dim_calc_stats(const struct dim_sample *start,
+		    const struct dim_sample *end,
 		    struct dim_stats *curr_stats);
 
 /**
diff --git a/lib/dim/dim.c b/lib/dim/dim.c
index 83b65ac74d73..97c3d084ebf0 100644
--- a/lib/dim/dim.c
+++ b/lib/dim/dim.c
@@ -54,7 +54,8 @@ void dim_park_tired(struct dim *dim)
 }
 EXPORT_SYMBOL(dim_park_tired);
 
-bool dim_calc_stats(struct dim_sample *start, struct dim_sample *end,
+bool dim_calc_stats(const struct dim_sample *start,
+		    const struct dim_sample *end,
 		    struct dim_stats *curr_stats)
 {
 	/* u32 holds up to 71 minutes, should be enough */