diff --git a/src/amd/common/ac_surface.c b/src/amd/common/ac_surface.c
index 9f7ab8162ce..1e77c4154c7 100644
--- a/src/amd/common/ac_surface.c
+++ b/src/amd/common/ac_surface.c
@@ -2127,6 +2127,7 @@ static int gfx9_compute_miptree(struct ac_addrlib *addrlib, const struct radeon_
 
          surf->cmask_size = cout.cmaskBytes;
          surf->cmask_alignment = cout.baseAlign;
+         surf->cmask_slice_size = cout.sliceSize;
       }
    }